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<h1>Details of Ghostscript output devices</h1>
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<h2>Table of contents</h2>
<blockquote><ul>
<li><a href="#Measurements">Notes on measurements</a>
<li><a href="#IJS">IJS - Inkjet and other raster devices</a>
<li><a href="#Win">MS Windows printers</a>
<li><a href="#File_formats">File formats</a>
<ul>
<li><a href="#JFIF">JPEG file format (JFIF)</a>
<li><a href="#TIFF">TIFF file formats</a>
</ul>
<li><a href="#Display_devices">Display devices</a>
<ul>
<li><a href="#x11_devices">X Window System</a>
</ul>
<li><a href="#HP_ijs">HP Deskjet official drivers</a>
<li><a href="#STP">Gimp-Print (stp) drivers</a>
<li><a href="#HP8_color_inkjet">H-P 8xx, 1100, and 1600 color inkjet printers</a>
<ul>
<li><a href="#HP8_gdevcd8">Drivers contained in <b><tt>gdevcd8.c</tt></b></a>
<li><a href="#HP8_further_documentation">Further documentation</a>
</ul>
<li><a href="#HP880_color_inkjet">H-P 812, 815, 832, 880, 882, 895, and 970 color inkjet printers</a>
<ul>
<li><a href="#HP880_gdevcd8">Drivers contained in <b><tt>gdevcd8.c</tt></b></a>
<li><a href="#HP880_further_documentation">Further documentation</a>
</ul>
<li><a href="#HP_color_inkjet">Other H-P color inkjet printers</a>
<ul>
<li><a href="#HP_gdevcdj">Drivers contained in <b><tt>gdevcdj.c</tt></b></a>
<li><a href="#HP_paper_size">Default paper size</a>
<li><a href="#HP_limits">Deskjet physical limits</a>
<li><a href="#HP_command_line">Printer properties (command-line parameters)</a>
<ul>
<li><a href="#HP_bpp">Bits per pixel</a>
<li><a href="#HP_deskjet_properties">Deskjet properties</a>
<li><a href="#HP_paintjet_properties">Paintjet XL300 / Paintjet XL properties</a>
</ul>
<li><a href="#HP_gamma">Gamma correction</a>
<li><a href="#HP_resolution_enhance">HP's resolution-enhanced mode for Inkjet printers</a>
<li><a href="#HP_tips">General tips</a>
</ul>
<li><a href="#BJC_8200">Canon BJC-8200 printer</a>
<li><a href="#BJC">Other Canon BubbleJet (BJC) printers</a>
<ul>
<li><a href="#BJC_history">History</a>
<li><a href="#BJC_build">Configuring and building the BJC drivers</a>
<ul>
<li><a href="#BJC_defaults">Modify values in <b><tt>gdevbjc.h</tt></b></a>
<li><a href="#BJC_CMYK_RGB">CMYK-to-RGB color conversion</a>
<li><a href="#BJC_vertical_centering">Vertical centering of the printable area</a>
<li><a href="#BJC_margins">Page margins</a>
<li><a href="#BJC_compile">Makefile and compilation</a>
</ul>
<li><a href="#BJC_usage">Use of the drivers</a>
<ul>
<li><a href="#BJC_options">Supported Options and Defaults</a>
<li><a href="#BJC_device_info">Device information</a>
<li><a href="#BJC_HW_margins">Hardware margins</a>
<li><a href="#BJC_PPD">PostScript printer description (PPD) files</a>
<li><a href="#BJC_PPD_custom">Customizing the PPD files</a>
</ul>
<li><a href="#BJC_bugs">How to report problems</a>
<li><a href="#BJC_acks">Acknowledgements</a>
</ul>
<li><a href="#STC_epson_stylus">Epson Stylus color printer (see also <b><tt>uniprint</tt></b>)</a>
<ul>
<li><a href="#STC_usage">Usage</a>
<li><a href="#STC_options">Options</a>
<li><a href="#STC_FAQ">Application note and FAQ</a>
<ul>
<li><a href="#STC_FAQ_A3">Support for A3 paper</a>
<li><a href="#STC_FAQ_margins">Margins, PageSize</a>
<li><a href="#STC_FAQ_II_IIS_1500">Stylus Color II / IIs and 1500</a>
</ul>
<li><a href="#STC_recommendations">Recommendations</a>
<ul>
<li><a href="#STC_dither_experiment">Color dithering experiments with <b><tt>gdevstc</tt></b> 1.21</a>
</ul>
<li><a href="#STC_color_transform">Color transformation</a>
<li><a href="#STC_CAM"><b><tt>ColorAdjustMatrix</tt></b></a>
<li><a href="#STC_RGBCMYK_coding">RGB / CMYK coding and transfer, and <b><tt>BitsPerPixel</tt></b></a>
<li><a href="#What_is_weaving">What is weaving?</a>
<li><a href="#STC_print_modes">Print mode parameters</a>
<ul>
<li><a href="#STC_unidirectional"><b><tt>Unidirectional</tt></b></a>
<li><a href="#STC_noweave"><b><tt>Microweave</tt></b>, <b><tt>noWeave</tt></b> and <b><tt>OutputCode=deltarow</tt></b></a>
<li><a href="#STC_model"><b><tt>Model</tt></b></a>
</ul>
<li><a href="#STC_Pitfalls">Bugs and pitfalls</a>
<li><a href="#STC_Tests">Tests</a>
<ul>
<li><a href="#STC_OutputCodes">The various OutputCodes</a>
<li><a href="#STC_printing_time">Printing time related to other options</a>
</ul>
<li><a href="#STC_acks">Acknowledgments</a>
</ul>
<li><a href="#Uniprint">uniprint, a flexible unified printer driver</a>
<ul>
<li><a href="#Uni_state">The state of this driver</a>
<li><a href="#Uni_background">Notes on <b><tt>uniprint</tt></b>'s background</a>
<li><a href="#Uni_make_pfile">Godzilla's guide to the creation of Unified Printer Parameter (<b><tt>.upp</tt></b>) files</a>
<li><a href="#Uni_all_parameters">All parameters in brief</a>
<li><a href="#Uni_honors"><b><tt>Uniprint</tt></b>'s Roll of Honor</a>
<li><a href="#Uni_weaving_howto"><b><tt>Uniprint</tt></b> weaving parameters howto</a></li>
<li><a href="#Uni_esc300">Extension to <b><tt>uniprint</tt></b> for the Epson Stylus Color 300</a></li>
</ul>
<li><a href="#SPARCprinter">Sun SPARCprinter</a>
<ul>
<li><a href="#SPARC_install">Installation</a>
<li><a href="#SPARC_problems">Problems</a>
</ul>
<li><a href="#Apple">Apple dot matrix printer</a>
</ul></blockquote>
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<p>For other information, see the <a href="Readme.htm">Ghostscript
overview</a>. You may also be interested in <a href="Make.htm">how to
build Ghostscript</a> and <a href="Install.htm">install it</a>, as well as
the description of the <a href="Drivers.htm">driver interface</a>.
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<hr>
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<h2><a name="Measurements"></a>Notes on measurements</h2>
<p>
Several different important kinds of measures appear throughout this
document: inches, centimeters and millimeters, points, and bits per pixel.
<dl>
<dt><b>Inches</b>
<dd>1 inch equals 2.54 centimeters. The inch measure is sometimes
represented by "<b>in</b>" or a quotation mark (<b>"</b>) to the right
of a measure, like <b>8.5in</b> or <b>8.5""</b>. Dots per inch,
"<b>dpi</b>", are the common measure of printing resolution for dot-matrix,
laser, and ink-jet printers. U.S. "letter" paper is exactly
8.5in×11in, approximately 21.6cm×27.9cm. (See in the usage
documentation all the <a href="Use.htm#Known_paper_sizes">paper sizes
predefined in Ghostscript</a>.)
<dt><b>Centimeters</b> and <b>millimeters</b>
<dd>ISO standard paper sizes such as A4 and A3 are commonly represented in
the SI units of centimeters and millimeters. Centimeters are abbreviated
"<b><tt>cm</tt></b>", millimeters "<b><tt>mm</tt></b>". ISO A4 paper is
quite close to 21.0×29.7 centimeters (approximately 8.3×11.7
inches).
<dt><b>Points</b>
<dd>Points are a measure traditionally used in the printing trade and now
in PostScript, which specifies exactly 72 points per inch (approximately
28.35 per centimeter). The <a href="Use.htm#Known_paper_sizes">paper sizes
known to Ghostscript</a> are defined in the initialization file
<b><tt>gs_statd.ps</tt></b> in terms of points.
<dt><b>Bits per pixel</b>
<dd>Commonly abbreviated "<b><tt>bpp</tt></b>".
</dl>
<hr>
<h2><a name="IJS"></a>IJS - Inkjet and other raster devices</h2>
<p>
IJS is a relatively new initiative to improve the quality and ease of
use of inkjet printing with Ghostscript. Using IJS, you can add new
drivers, or upgrade existing ones, without recompiling Ghostscript.
All driver authors are encouraged to adapt their drivers for IJS, and
if there is an IJS driver available for your printer, it should be
your first choice.
</p>
<p>Please see the <a href="http://www.linuxprinting.org/ijs/">IJS web
page</a> for more information about IJS, including a listing of
IJS-compatible drivers.
</p>
<p>
A typical command line for IJS is:
</p>
<blockquote>
<b><tt>
gs -DSAFER -sDEVICE=ijs -sIjsServer=hpijs
-sDeviceManufacturer=HEWLETT-PACKARD -sDeviceModel='DESKJET 990'
-DIjsUseOutputFD -sOutputFile=/dev/usb/lp1 -DNOPAUSE --
examples/tiger.eps
</tt></b>
</blockquote>
<p>
Individual IJS command line parameters are as follows:
</p>
<dl>
<dt><b><tt>-sIjsServer=</tt></b><em>{path}</em>
<dd>Sets the pathname for the IJS server (ie printer driver). Examples
are "hpijs" and "ijsgimpprint".
Ghostscript will spawn a new process for this driver, and communicate
with it using the IJS protocol. The pathname need not be absolute,
as the PATH environment variable is searched, but it's probably a good
idea for robustness and security. Note also that if -dSAFER is not
specified, it's possible for PostScript code to set this parameter,
so it can cause arbitrary code to be executed. See the section on <a
href="Use.htm#Security">Security</a> for more information.
</dl>
<dl>
<dt><b><tt>-sDeviceManufacturer=</tt></b><em>{name}</em>
<dt><b><tt>-sDeviceModel=</tt></b><em>{name}</em>
<dd>These parameters select the device according to IEEE-1284 standard
device ID strings. In general, consult the documentation for the
driver to find the appropriate settings. Note that, if the value
contains a space, you'll want to quote the value in your shell, as
in the example above.
</dl>
<dl>
<dt><b><tt>-sIjsParams=</tt></b><em>{params}</em>
<dd>This parameter allows you to set arbitrary IJS parameters on
the IJS driver. The format is a comma-separated list of
<b><tt>key=value</tt></b> pairs. If it is necessary to send a
value containing a comma or backslash, it can be escaped with
a backslash. Thus, <b><tt>'-sIjsParams=Foo=bar,Baz=a\,b'</tt></b> sets
the parameter Foo to "bar", and Baz to "a,b".
</dl>
<dl>
<dt><b><tt>-dIjsUseOutputFD</tt></b>
<dd>This flag indicates that Ghostscript should open the output file
and pass a file descriptor to the server. If not set, Ghostscript
simply passes the filename set in OutputFile to the server. In most
cases, this flag won't matter, but if you have a driver which works
only with OutputFD (such as hpijs 1.0.2), or if you're using the
-sOutputFile="|cmd" syntax, you'll need to set it.
</dl>
<dl>
<dt><b><tt>-dBitsPerSample=</tt></b><em>N</em>
<dd>This parameter controls the number of bits per sample. The
default value of 8 should be appropriate for most work. For monochrome
images, use -dBitsPerSample=1.
</dl>
<p>Generic Ghostscript options that are particularly relevant for IJS
are summarized below:
</p>
<dl>
<dt><b><tt>-r</tt></b><em>number</em>
<br><b><tt>-r</tt></b><em>number1</em><b><tt>x</tt></b><em>number2</em>
<dd>Sets the resolution, in dpi. If the resolution is not specified,
Ghostscript queries the IJS server to determine the preferred resolution.
When the resolution is specified, it overrides the value (if any)
preferred by the IJS server.
</dl>
<dl>
<dt><b><tt>-dDuplex</tt></b>
<dt><b><tt>-dTumble</tt></b>
<dd>These flags enable duplex (two-sided) printing. Tumble controls
the orientation. When Tumble is false, the pages
are oriented suitably at the left or right. When Tumble is true,
the pages are oriented suitably for binding at the top or
bottom.
</dl>
<dl>
<dt><b><tt>-sProcessColorModel=</tt></b><em>{name}</em>
<dd>Use this flag to select the process color model. Suitable values
include DeviceGray, DeviceRGB, and DeviceCMYK.
</dl>
<h3>Building IJS</h3>
<p> IJS is included by default on Unix gcc builds, and also in
autoconf'ed builds. Others may need some makefile tweaking. First,
make sure the IJS device is selected:
<blockquote>
DEVICE_DEVS2=$(DD)ijs.dev
</blockquote>
<p> Next, make sure that the path and execution type are set in
the toplevel makefile. The values for Unix are as follows:
<blockquote>
IJSSRCDIR=ijs
IJSEXECTYPE=unix
</blockquote>
<p> At present, "unix" and "win" are the only supported values for
IJSEXECTYPE. If neither sounds appropriate for your system, it's
possible that more porting work is needed.
<p> Last, make sure that ijs.mak is included in the toplevel makefile.
It should be present right after the include of icclib.mak.
<p> IJS is not inherently platform-specific. We're very much interested
in taking patches from people who have ported it to non-mainstream
platforms. And once it's built, you won't have to recompile Ghostscript
to support new drivers!
<h2><a name="Win"></a>MS Windows printers</h2>
<p>
This section was written by Russell Lang, the author of Ghostscript's
MS Windows-specific printer driver, and updated by
<a href="mailto:Pierre.Arnaud@opac.ch">Pierre Arnaud</a>,
the current maintainer.
</p>
<p>
The <b><tt>mswinpr2</tt></b> device uses MS Windows printer drivers, and
thus should work with any printer with device-independent bitmap (DIB)
raster capabilities. The printer resolution cannot be selected directly
using PostScript commands from Ghostscript: use the printer setup in the
Control Panel instead. It is however possible to specify a maximum resolution
for the printed document (see below).
</p>
<p>
If no Windows printer name is specified in <b><tt>-sOutputFile</tt></b>,
Ghostscript prompts for a Windows printer using the standard Print Setup
dialog box. You must set the orientation to Portrait and the page size to
that expected by Ghostscript; otherwise the image will be clipped.
Ghostscript sets the physical device size to that of the Windows printer
driver, but it does not update the PostScript clipping path.
</p>
<p>
If a Windows printer name is specified in <b><tt>-sOutputFile</tt></b> using
the format <tt>"\\spool\printer_name"</tt>, for instance
</p>
<blockquote><b><tt>
gs ... -sOutputFile="\\spool\Apple LaserWriter II NT"
</tt></b></blockquote>
<p>
then Ghostscript attempts to open the Windows printer without prompting
(except, of course, if the printer is connected to <b><tt>FILE:</tt></b>).
Ghostscript attempts to set the Windows printer page size and orientation
to match that expected by Ghostscript, but doesn't always succeed. It uses
this algorithm:
</p>
<ol>
<li>If the requested page size matches one of the Windows standard page
sizes +/- 2mm, request that standard size.</li>
<li>Otherwise if the requested page size matches one of the Windows
standard page sizes in landscape mode, ask for that standard size in
landscape.</li>
<li>Otherwise ask for the page size by specifying only its dimensions.</li>
<li>Merge the requests above with the defaults. If the printer driver
ignores the requested paper size, no error is generated: it will print on
the wrong paper size.</li>
<li>Open the Windows printer with the merged orientation and size.</li>
</ol>
<p>
The Ghostscript physical device size is updated to match the Windows
printer physical device.
</p>
<h3><a name="Win_properties"></a>Supported command-line parameters</h3>
<p>
The <b><tt>mswinpr2</tt></b> device supports a limited number of command-line
parameters (e.g. it does not support setting the printer resolution). The
recognized parameters are the following:
</p>
<blockquote>
<dl>
<dt><b><tt>-sDEVICE=mswinpr2</tt></b></dt>
<dd>Selects the MS Windows printer device. If Ghostscript was not
compiled with this device as the default output device, you have to specify
it on the command line.</dd>
<dt><b><tt>-dNoCancel</tt></b></dt>
<dd>Hides the progress dialog, which shows the percent of the document page
already processed and also provides a <em>cancel</em> button. This option
is useful if GS is intended to print pages in the background, without any
user intervention.</dd>
<dt><b><tt>-sOutputFile=</tt></b><b>"\\spool\<em>printer_name</em>"</b></dt>
<dd>Specifies which printer should be used. The <em>printer_name</em> should be
typed exactly as it appears in the Printers control panel, including spaces.</dd>
</dl>
</blockquote>
<h3><a name="Win_options"></a>Supported options (device properties)</h3>
<p>
Several extra options exist which cannot be set through the command-line,
but only by executing the appropriate PostScript setup code. These options
can be set through the inclusion of a setup file on the command-line:
</p>
<blockquote><b><tt>
gs ... setup.ps ...
</tt></b></blockquote>
<p>
The <tt>setup.ps</tt> file is responsible for the device selection, therefore
you should not specify the <b><tt>-sDEVICE=mswinpr2</tt></b> option on the
command-line if you are using such a setup file. Here is an example of such
a setup file:
</p>
<blockquote><pre>
mark
/NoCancel true % don't show the cancel dialog
/BitsPerPixel 4 % force 4 bits/pixel
/UserSettings
<<
/DocumentName (Ghostscript document) % name for the Windows spooler
/MaxResolution 360 % maximum document resolution
>>
(mswinpr2) finddevice % select the Windows device driver
putdeviceprops
setdevice
</pre></blockquote>
<p>
This example disables the progress dialog (same as the <tt><b>-dNoCancel</b></tt>
option), forces a 4 bits/pixel output resolution and specifies additional user
settings, such as the document name (which will be displayed by the Windows
spooler for the queued document) and the maximum resolution (here 360 dpi).
It then finds and selects an instance of the MS Windows device printer
and activates it. This will show the standard printer dialog, since no
<tt><b>/OutputFile</b></tt> property was specified.
</p>
<p>
The following options are available:
</p>
<blockquote>
<dl>
<dt><b><tt>/NoCancel <em>boolean</em></tt></b></dt>
<dd>Disables (hides) the progress dialog when set to <em><tt>true</tt></em> or
show the progress dialog if not set or set to <em><tt>false</tt></em>.</dd>
<dt><b><tt>/OutputFile <em>string</em></tt></b></dt>
<dd>Specifies which printer should be used. The string should be of the form
<tt><b>\\spool\<em>printer_name</em></b></tt>, where the <em>printer_name</em> should be
typed exactly as it appears in the Printers control panel, including spaces.</dd>
<dt><b><tt>/QueryUser <em>integer</em></tt></b></dt>
<dd>Shows the standard printer dialog (<tt><b>1</b></tt> or any other value),
shows the <em>printer setup dialog</em> (<tt><b>2</b></tt>) or selects the
<em>default Windows printer</em> without any user interaction (<tt><b>3</b></tt>).</dd>
<dt><b><tt>/BitsPerPixel <em>integer</em></tt></b></dt>
<dd>Sets the device depth to the specified bits per pixel. Currently supported
values are <tt><b>1</b></tt> (monochrome), <tt><b>4</b></tt> (CMYK with screening
handled by Ghostscript) and <tt><b>24</b></tt> (True Color, dithering handled by
the Windows printer driver; this option can produce huge print jobs).</dd>
<dt><b><tt>/UserSettings <em>dict</em></tt></b></dt>
<dd>Sets additional options, defined in a dictionary. The following properties can
be set:
<dl>
<dt><b><tt>/DocumentName <em>string</em></tt></b></dt>
<dd>Defines the user friendly document name which will be displayed by the
Windows spooler.</dd>
<dt><b><tt>/DocumentRange <em>[n1 n2]</em></tt></b></dt>
<dd>Defines the range of pages contained in the document. This information can
be used by the printer dialog, in conjunction with the following property.</dd>
<dt><b><tt>/SelectedRange <em>[n1 n2]</em></tt></b></dt>
<dd>Defines the selected range of pages. This information will be displayed in
the printer dialog and will be updated after the user interaction. A PostScript
program could check these values and print only the selected page range.</dd>
<dt><b><tt>/MaxResolution <em>dpi</em></tt></b></dt>
<dd>Specifies the maximum tolerated output resolution. If the selected printer has
a higher resolution than <tt><b>dpi</b></tt>, then Ghostscript will render the
document with a submultiple of the printer resolution. For example, if
<tt><b>MaxResolution</b></tt> is set to 360 and the output printer supports
up to 1200 dpi, then Ghostscript renders the document with an internal
resolution of 1200/4=300 dpi. This can be very useful to reduce the memory
requirements when printing in True Color on some high resolution ink-jet color
printers.</dd>
</dl></dd>
</dl>
</blockquote>
<p>
These properties can be queried through the <tt><b>currentpagedevice</b></tt>
operator. The following PostScript code snippet shows how to do it for some
of the properties:
</p>
<blockquote><pre>
currentpagedevice /BitsPerPixel get == % displays the selected depth
currentpagedevice /UserSettings get % get the additional options..
/us exch def % ..and assign them to a variable
us /DocumentName get == % displays the document name
us /SelectedRange get == % displays the selected page range
% other misc. informations (don't rely on them)
us /Color get == % 1 => monochrome output, 2 => color output
us /PrintCopies get == % displays the number of copies requested
</pre></blockquote>
<p>
There are a few undocumented informations stored in the <tt><b>UserSettings</b></tt>
dictionary. You should not rely on them. Their use is still experimental and
they could be removed in a future version.
</p>
<h3><a name="Win_duplex"></a>Duplex printing</h3>
<p>
If the Windows printer supports the duplex printing feature, then it will
also be available through the <b><tt>mswinpr2</tt></b> device. You can query
for this support through the <b><tt>/Duplex</tt></b> propery of the
<b><tt>currentpagedevice</tt></b>. If it returns <b><tt>null</tt></b>, then
the feature is not supported by the selected printer. Otherwise, <b><tt>true</tt></b>
means that the printer is currently set up to print on both faces of the paper
and <b><tt>false</tt></b> that it is not, but that it can.
</p>
<p>
The following example shows how to print on both faces of the paper (using
the long side of the paper as the reference):
</p>
<blockquote><pre>
<< /Duplex true /Tumble false >> setpagedevice
</pre></blockquote>
<p>
</p>
<hr>
<h2><a name="File_formats"></a>File formats</h2>
<h3><a name="JFIF"></a>JPEG file format (JFIF)</h3>
<p>
Ghostscript includes output drivers that can produce <a
href="http://www.ijg.org/">Independent JPEG Group</a> JFIF (JPEG File
Interchange Format) files from PostScript images. <b>Please note</b> that
JPEG is a compression method specifically intended for continuous-tone
images such as photographs, not for graphics, and it is therefore quite
unsuitable for the vast majority of page images produced with PostScript,
which should be saved in a form better for graphics, such as
<a href="http://www.libpng.org/pub/png/">Portable Network Graphics</a>
(PNG) format. If you get crummy-looking JPEG files, don't blame
Ghostscript; instead consult a reference about uses and abuses of JPEG,
such as the JPEG FAQ
<blockquote>
<a href="http://www.faqs.org/faqs/jpeg-faq/">http://www.faqs.org/faqs/jpeg-faq/</a>
</blockquote>
<p>
You can use the JPEG output drivers -- <b><tt>jpeg</tt></b> to produce
color JPEG files and <b><tt>jpeggray</tt></b> for grayscale JPEGs -- the
same as other file-format drivers: by specifying the device name and an
output file name, for example
<blockquote><b><tt>
gs -sDEVICE=jpeg -sOutputFile=foo.jpg foo.ps
</tt></b></blockquote>
<p>
You can also use the <a href="Use.htm#Resolution_switch"><b><tt>-r</tt></b>
switch</a> to specify the imaging resolution and thus the output file's
size in pixels. The default resolution is normally 72×72dpi.
<p>
The JPEG devices support several special parameters to control the JPEG
"quality setting" (DCT quantization level).
<blockquote>
<dl>
<dt><b><tt>-dJPEGQ=</tt></b><b><em>N</em></b> (integer from 0 to 100, default 75)
<dd>Set the quality level <b><em>N</em></b> according to the widely used
IJG quality scale, which balances the extent of compression against the
fidelity of the image when reconstituted. Lower values drop more
information from the image to achieve higher compression, and therefore
have lower quality when reconstituted.
<dt><b><tt>-dQFactor=</tt></b><b><em>M</em></b> (float from 0.0 to 1.0)
<dd>Adobe's QFactor quality scale, which you may use in place of
<b><tt>JPEGQ</tt></b> above. The QFactor scale is used by PostScript's
DCTEncode filter but is nearly unheard-of elsewhere.
</dl>
</blockquote>
<p>
At this writing the default JPEG quality level of 75 is equivalent to
<b><tt>-dQFactor=0.5</tt></b>, but the JPEG default might change in the
future. The JPEG drivers could be extended to support additional JPEG
compression options, such as the other DCTEncode filter parameters, but so
far they haven't been.
<h3><a name="TIFF"></a>TIFF file formats</h3>
<p>
There are two unrelated sets of TIFF drivers. There are two color TIFF
drivers that produce uncompressed output:
<blockquote>
<dl>
<dt><b><tt>tiff12nc</tt></b>
<dd>Produces 12-bit RGB output (4 bits per component).
<dt><b><tt>tiff24nc</tt></b>
<dd>Produces 24-bit RGB output (8 bits per component).
</dl>
</blockquote>
<p>
The remaining TIFF drivers all produce black-and-white output with different
compression modes:
<blockquote>
<dl>
<dt><b><tt>tiffcrle</tt></b>
<dd>G3 fax encoding with no EOLs
<dt><b><tt>tiffg3</tt></b>
<dd>G3 fax encoding with EOLs
<dt><b><tt>tiffg32d</tt></b>
<dd>2-D G3 fax encoding
<dt><b><tt>tiffg4</tt></b>
<dd>G4 fax encoding
<dt><b><tt>tifflzw</tt></b>
<dd>LZW-compatible (tag = 5) compression
<dt><b><tt>tiffpack</tt></b>
<dd>PackBits (tag = 32773) compression
</dl>
</blockquote>
<p>
The black-and-white TIFF drivers support creation of files that are
comprised of more than a single strip. Multi-strip files reduce the memory
requirement on the reader, since readers need only store and process one
strip at a time. These drivers provide two parameters beyond the standard
set:
<blockquote>
<dl>
<dt><b><tt>-dMaxStripSize=</tt><em>N</em></b> (non-negative integer; default = 0)
<dd>Set the maximum (uncompressed) size of a strip.
<dt><b><tt>-dAdjustWidth=</tt><em>true|false</em></b> (Boolean; default =
true)
<dd>If true, then if the requested page width is close to either A4 (1728
columns) or B4 (2048 columns), set the page width to A4 or B4 respectively.
</dl></blockquote>
<p>
The TIFF 6.0 specification, Section 7, page 27, recommends that the size of
each strip be about 8 Kbytes. As an example, to generate the 'tiger' in
tiffg4 format that has the recommended strip size, use:
<blockquote><pre>
gs -sDEVICE=tiffg4 -sOutputFile=tiger.tif -dMaxStripSize=8192 examples/tiger.ps
</pre></blockquote>
<p>
If the value of the <b><tt>MaxStripSize</tt></b> parameter is smaller than a
single image row, then no error will be generated, and the TIFF file will be
generated correctly using one row per strip. Note that smaller strip sizes
increase the size of the file by increasing the size of the StripOffsets and
StripByteCounts tables, and by reducing the effectiveness of the compression
which must start over for each strip.
<p>
If the value of MaxStripSize is 0 (the default), then the entire image will
be a single strip.
<hr>
<h2><a name="Display_devices"></a>Display Devices</h2>
<p>
Ghostscript is often used for screen display of postscript and pdf documents.
In many cases, a client or 'viewer' application calls the ghostscript engine
to do the rasterization and handles the display of the resulting image itself,
but it is also possible to invoke ghostscript directly and select an output
device which directly handles displaying the image on screen.
<p>
This section describes the various display-oriented devices that are available
in ghostscript.
<h3><a name="x11_devices"></a>X Window System</h3>
<p>
Perhaps the most common use of of a display device is with the X Window System
on unix-like systems. It is the default device on the command line client on
such systems, and is used more creatively by the gv client application.
<p>
The available devices are:
<dl>
<dt><b>x11</b>
<dd>This is the default device, handling display on X11R6.
<dt><b>x11alpha</b>
<dd>This is the x11 device, but with antialiasing. It is equivalent to
invoking the x11 device with the options <tt>-dGraphicsAlphaBits=4
-dTextAlphaBits=4 -dMaxBitmap=50000000</tt>.
<dt><b>x11cmyk</b>
<dd>This device rasterizes the image in the CMKY color space, then flattens
it to RGB for display. It's intended for testing only.
<dt><b>x11mono</b>
<dd>This is a strict black-and-white device for 1-bit monochrome displays.
<dt><b>x11gray2</b>
<dd>This is a device for 2 bpp (4-level) monochrome displays.
<dt><b>x11gray4</b>
<dd>This is a device for 4 bpp (16-level) monochrome displays.
</dl>
<hr>
<h2><a name="HP_ijs"></a>HP Deskjet official drivers</h2>
<p>
HP provides official drivers for many of their Deskjet printer models.
In order to use these drivers, you will need the HP Inkjet Server as
well as Ghostscript, available from <a
href="http://hpinkjet.sourceforge.net">http://hpinkjet.sourceforge.net</a>.
This version of Ghostscript includes the patch from version 0.97 of
the hpijs software. If you are installing hpijs from an RPM, you will
only need the hpijs RPM, not the ghostscript-hpijs one, as the code
needed to work with hpijs is already included.
<p>
Note that newer version of the hpijs drivers support the IJS protocol.
If you can, you should consider using the ijs driver instead. Among
other things, the hpijs Ghostscript driver is Unix-only, and is untested
on older Unix platforms.
<p>
As of the 0.97 version, hpijs supports the following printer models:
<dl><dt><b>e-Series:</b>
<dd>e-20
<dt><b>DeskJet 350C Series:</b>
<dd>350C
<dt><b>DeskJet 600C Series:</b>
<dd>600C, 660C, 670/672C, 670TV, 680/682C
<dt><b>DeskJet 600C Series Photo:</b>
<dd>610/612C, 640/648C, 690/692/693/694/695/697C
<dt><b>DeskJet 630C Series:</b>
<dd>630/632C
<dt><b>DeskJet 800C Series:</b>
<dd>810/812C, 830/832C, 840/842/843C, 880/882C, 895C
<dt><b>DeskJet 900C Series, PhotoSmart::</b>
<dd>930/932C, 950/952C, 970C, PhotoSmart 1000/1100
<dt><b>DeskJet 990C, PhotoSmart:</b>
<dd>960C, 980C, 990C, PhotoSmart 1215/1218
</dl>
<p>You will need to add the following line to your makefile:
<blockquote>
DEVICE_DEVS2=$(DD)DJ630.dev $(DD)DJ6xx.dev $(DD)DJ6xxP.dev $(DD)DJ8xx.dev $(DD)DJ9xx.dev $(DD)DJ9xxVIP.dev $(DD)AP21xx.dev
</blockquote>
<p>
Please see <a
href="http://hpinkjet.sourceforge.net">http://hpinkjet.sourceforge.net</a>
for more information about this driver. Thanks to the folks at HP,
especially David Suffield for making this driver available and working to
integrate it with Ghostscript.
<hr>
<h2><a name="STP"></a>Gimp-Print (stp) drivers</h2>
<p>
Ghostscript includes a client device for the Gimp-Print family of
drivers. The device itself is called <tt>stp</tt> for historical
reasons. Please see <a href="http://gimp-print.sourceforge.net/"
class="offsite">http://gimp-print.sourceforge.net/</a> for more
information.
<p>
You will need to have the Gimp-Print library installed to use this
device. The library distribution also includes extensive documentation
on supported printers and the options available with each. Thanks to the
Gimp-Print team for all their hard work integrating their excellent
driver suite.
<p>
Please note that the stp driver interface is only supported through
gimp-print version 4.2. If you have 4.2.1 or later, please use the IJS
interface (described above) instead.
<hr>
<h2><a name="HP8_color_inkjet"></a>H-P 8xx, 1100, and 1600 color inkjet printers</h2>
<p>
This section, written by Uli Wortmann <<a
href="mailto:uliw@erdw.ethz.ch">uliw@erdw.ethz.ch</a>>, deals with the
DeskJet 670, 690, 850, 855, 870, 890, 1100, and 1600.
<h3><a name="HP8_gdevcd8"></a>Drivers contained in <b><tt>gdevcd8.c</tt></b></h3>
<p>
The source module <b><tt>gdevcd8.c</tt></b> contains four generic drivers:
<blockquote><table cellpadding=0 cellspacing=0>
<tr valign=top> <td><b><tt>cdj670</tt></b>
<td>
<td>HP DeskJet 670 and 690
<tr valign=top> <td><b><tt>cdj850</tt></b>
<td>
<td>HP DeskJet 850, 855, 870, and 1100
<tr valign=top> <td><b><tt>cdj890</tt></b>
<td>
<td>HP DeskJet 890
<tr valign=top> <td><b><tt>cdj1600</tt></b>
<td>
<td>HP DeskJet 1600
</table></blockquote>
<h3><a name="HP8_further_documentation"></a>Further documentation</h3>
<p>
<b>Credits:</b> Much of the driver is based on ideas derived from the
cdj550 driver of George Cameron. The support for the hp670, hp690, hp890
and hp1600 was added by Martin Gerbershagen.
<blockquote><table cellpadding=0 cellspacing=0>
<tr valign=top> <td>11.11.96
<td>
<td>Version 1.0
<td>
<td>
<tr valign=top> <td>25.08.97
<td>
<td>Version 1.2
<td>
<td>Resolved all but one of the known bugs, introduced a couple of
perfomance improvements. Complete new color-transfer-function
handling (see gamma).
<tr valign=top> <td>01.06.98
<td>
<td>Version 1.3
<td>
<td>Due to the most welcome contribution of Martin Gerbershagen
(ger@ulm.temic.de), support for the hp670, hp690 and hp890 and
hp1600 has been added. Martin has also resolved all known bugs.
<tr valign=top> <td>
<td>
<td>
<td>
<td>Problems:Dark colors are still pale.
</table></blockquote>
<p>
The hp690 is supported through the hp670 device, the hp855, hp870 and the
hp1100 through the hp850 device. The driver needs no longer special
switches to be invoked except <b><tt>-sDEVICE=cdj850</tt></b>,
<b><tt>-sDEVICE=CDJ890</tt></b>, <b><tt>-sDEVICE=CDJ670</tt></b>, or
<b><tt>-sDevice=CDJ1600</tt></b>. The following switches are supported.
<blockquote><table cellpadding=0 cellspacing=0>
<tr valign=top> <td><b><tt>-dPapertype=</tt></b>
<td>
<td>0
<td>
<td>plain paper [default]
<tr valign=top> <td>
<td>
<td>1
<td>
<td>bond paper
<tr valign=top> <td>
<td>
<td>2
<td>
<td>special paper
<tr valign=top> <td>
<td>
<td>3
<td>
<td>glossy film
<tr valign=top> <td>
<td>
<td>4
<td>
<td>transparency film
<tr valign=top> <td>
<td>
<td>
<td>
<td>Currently the lookup tables are unsuited for printing on
special paper or transparencies. For these please revert to the
gamma functions.
<tr valign=top> <td><b><tt>-dQuality=</tt></b>
<td>
<td>-1
<td>
<td>draft
<tr valign=top> <td>
<td>
<td>0
<td>
<td>normal [default]
<tr valign=top> <td>
<td>
<td>1
<td>
<td>presentation
<tr valign=top> <td><b><tt>-dRetStatus=</tt></b>
<td>
<td>0
<td>
<td>C-RET off
<tr valign=top> <td>
<td>
<td>1
<td>
<td>C-RET on [default]
<tr valign=top> <td><b><tt>-dMasterGamma=</tt></b>
<td>
<td>3.0
<td>
<td>[default = 1.0]
</table></blockquote>
<blockquote>
<b>Note:</b> To take advantage of the calibrated color-transfer functions,
be sure not to have any gamma statements left! If you need to (i.e., for
overhead transparencies), you still can use the gamma functions, but they
will override the built-in calibration. To use gamma in the traditional
way, set MasterGamma to any value greater than 1.0 and less than 10.0. To
adjust individual gamma values, you have to additionally set MasterGamma to
a value greater than 1.0 and less than 10.0. With the next release, gamma
functions will be dropped.
</blockquote>
<p>
When using the driver, be aware that printing at 600dpi involves
processing large amounts of data (> 188MB !). Therefore the
driver is not what you would expect to be a fast driver ;-)
This is no problem when printing a full-sized color page (because
printing itself is slow), but it's really annoying if you print only
text pages. Maybe I can optimize the code for text-only pages in a
later release. Right now, it is recommended to use the highest
possible optimisation level your compiler offers.
For the time being, use the cdj550 device with <b><tt>-sBitsPerPixel=3</tt></b>
for fast proof prints. If you simply want to print 600dpi BW data,
use the cdj550 device with <b><tt>-sBitsPerPixel=8</tt></b> (or 1).
<p>
Since the printer itself is slow, it may help to set the process priority
of the gs process to "regular" or even less. On a 486/100MHz this is still
sufficient to maintain a continuous data flow. Note to OS/2 users: simply
put the gs window into the background or minimize it. Also make sure that
<b><tt>print01.sys</tt></b> is invoked without the <b><tt>/irq</tt></b>
switch (great speed improvement under Warp4).
<p>
The printer default settings compensate for dot-gain by a calibrated
color-transfer function. If this appears to be too light for your business
graphs, or for overhead transparencies, feel free to set
<b><tt>-dMasterGamma=1.7</tt></b>. Furthermore, you may tweak the gamma
values independently by setting <b><tt>-dGammaValC</tt></b>,
<b><tt>-dGammaValM</tt></b>, <b><tt>-dGammaValY</tt></b> or
<b><tt>-dGammaValK</tt></b> (if not set, the values default to
<b><tt>MasterGamma</tt></b>). This will only work when
<b><tt>-dMasterGamma</tt></b> is set to a value greater than 1.0.
<p>
Further information, bugs, tips etc, can be found at my website. To learn
more about gamma, see
<a href="ftp://ftp.igd.fhg.de/pub/doc/colour/GammaFAQ.pdf">ftp://ftp.igd.fhg.de/pub/doc/colour/GammaFAQ.pdf</a>.
<p>
Depending on how you transfer the files, under UNIX you may need to remove
the CRs of the CR-LF sequence used for end-of-line on DOS-based (MS
Windows-based) systems. You can do this in unpacking the files with <b><tt>unzip -a hp850.zip</tt></b>.
<p>
To compile with gs5.x or later, simply add to your makefile
<blockquote>
DEVICE_DEVS4=cdj850.dev cdj670.dev cdj890.dev cdj1600.dev
</blockquote>
<p>
Have fun!
<p>
Uli <<a href="mailto:uliw@erdw.ethz.ch">uliw@erdw.ethz.ch</a>>
<br><a href="http://www.erdw.ethz.ch/~bonk/">http://www.erdw.ethz.ch/~bonk/</a>
<hr>
<h2><a name="HP880_color_inkjet"></a>H-P 812, 815, 832, 880, 882, 895, and 970 color inkjet printers</h2>
<p>
This section, written by Matthew Gelhaus <<a
href="mailto:hp880@gelhaus.net">hp880@gelhaus.net</a>>, deals with the
DeskJet 812, 815, 832, 880, 882, 895, and 970.
<p>
This is a modified version of the <a href="#HP8_color_inkjet">HP8xx driver</a>
written by Uli Wortmann. More information and download are available at
<a href="http://www.gelhaus.net/hp880c/">http://www.gelhaus.net/hp880c/</a>.
<h3><a name="HP880_gdevcd8"></a>Drivers contained in <b><tt>gdevcd8.c</tt></b></h3>
<p>
The source module <b><tt>gdevcd8.c</tt></b> contains one generic driver:
<blockquote><table cellpadding=0 cellspacing=0>
<tr valign=top> <td><b><tt>cdj880</tt></b>
<td>
<td>HP DeskJet 812, 815, 832, 880, 882, 895, and 970
</table></blockquote>
<h3><a name="HP880_further_documentation"></a>Further documentation</h3>
<p>
<b>Credits:</b> This driver is based on the cdj850 driver by Uli Wortmann, and shares the same
internal structure, although the PCL3+ interpretation has changed.
<blockquote><table cellpadding=0 cellspacing=0>
<tr valign=top> <td>15.03.99
<td>
<td>Version 1.3
<td>
<td>Initial version, based on Version 1.3 of Uli Wortmann's driver.
<tr valign=top> <td>26.02.00
<td>
<td>Version 1.4beta
<td>
<td>Greatly improved color handling & dithering, but not yet complete enough
to use for text.
</table></blockquote>
<p>
All printers are supported through the cdj880 device. Invoke with
<b><tt>-sDEVICE=cdj880</tt></b>. The following switches are supported.
<blockquote><table cellpadding=0 cellspacing=0>
<tr valign=top> <td><b><tt>-dPapertype=</tt></b>
<td>
<td>0
<td>
<td>plain paper [default]
<tr valign=top> <td>
<td>
<td>1
<td>
<td>bond paper
<tr valign=top> <td>
<td>
<td>2
<td>
<td>special paper
<tr valign=top> <td>
<td>
<td>3
<td>
<td>glossy film
<tr valign=top> <td>
<td>
<td>4
<td>
<td>transparency film
<tr valign=top> <td>
<td>
<td>
<td>
<td>Currently the lookup tables are unsuited for printing on
special paper or transparencies. For these please revert to the
gamma functions.
<tr valign=top> <td><b><tt>-dQuality=</tt></b>
<td>
<td>-1
<td>
<td>draft
<tr valign=top> <td>
<td>
<td>0
<td>
<td>normal [default]
<tr valign=top> <td>
<td>
<td>1
<td>
<td>presentation
<tr valign=top> <td><b><tt>-dMasterGamma=</tt></b>
<td>
<td>3.0
<td>
<td>[default = 1.0]
</table></blockquote>
<p>
The printer default settings compensate for dot-gain by a pre-defined
color-transfer function. If this appears to be too light for your business
graphs, or for overhead transparencies, feel free to set
<b><tt>-dMasterGamma=1.7</tt></b>. Furthermore, you may tweak the gamma
values independently by setting <b><tt>-dGammaValC</tt></b>,
<b><tt>-dGammaValM</tt></b>, <b><tt>-dGammaValY</tt></b> or
<b><tt>-dGammaValK</tt></b> (if not set, the values default to
<b><tt>MasterGamma</tt></b>). This will only work when
<b><tt>-dMasterGamma</tt></b> is set to a value greater than 1.0.
<p>
Further information, bugs, tips etc, can be found at my website.
<p>
To compile with gs6.x or later, simply add to your makefile
<blockquote>
DEVICE_DEVS4=$(DD)cdj880.dev
</blockquote>
<p>
Matthew Gelhaus <<a href="mailto:hp880@gelhaus.net">mailto:hp880@gelhaus.net</a>>
<br><a href="http://www.gelhaus.net/hp880c/">http://www.gelhaus.net/hp880c/</a>
<hr>
<h2><a name="HP_color_inkjet"></a>H-P color inkjet printers</h2>
<p>
This section, written by George Cameron, deals with the DeskJet 500C,
DeskJet 550C, PaintJet, PaintJet XL, PaintJet XL300, the DEC LJ250
operating in PaintJet-compatible mode.
<h3><a name="HP_gdevcdj"></a>Drivers contained in <b><tt>gdevcdj.c</tt></b></h3>
<p>
The source module <b><tt>gdevcdj.c</tt></b> contains six generic drivers:
<blockquote><table cellpadding=0 cellspacing=0>
<tr valign=top> <td><b><tt>cdj500</tt></b>
<td>
<td>HP DeskJet 500C and 540C
<tr valign=top> <td><b><tt>cdj550</tt></b>
<td>
<td>HP DeskJet 550C, 560C, 660C, 660Cse
<tr valign=top> <td><b><tt>pjxl300</tt></b>
<td>
<td>HP PaintJet XL300, DeskJet 1200C, and CopyJet
<tr valign=top> <td><b><tt>pjtest</tt></b>
<td>
<td>HP PaintJet
<tr valign=top> <td><b><tt>pjxltest</tt></b>
<td>
<td>HP PaintJet XL
<tr valign=top> <td><b><tt>declj250</tt></b>
<td>
<td>DEC LJ250
</table></blockquote>
<p>
All these drivers have 8-bit (monochrome), 16-bit and 24-bit (colour) and
for the DJ 550C, 32-bit (colour, CMYK mode) options in addition to standard
colour and mono drivers. It is also possible to set various
printer-specific parameters from the command line, for example
<blockquote><b><tt>
gs -sDEVICE=cDeskJet -dBitsPerPixel=16 -dDepletion=1 -dShingling=2 tiger.ps
</tt></b></blockquote>
<p>
<b>Note:</b> the old names <b><tt>cDeskJet</tt></b>,
<b><tt>cdjcolor</tt></b> and <b><tt>cdjmono</tt></b> drivers have been
retained; however, their functionality duplicates that available using the
drivers above (and <b><tt>cDeskJet</tt></b> is identical to
<b><tt>cdj500</tt></b>). That is, we can use
<blockquote><table cellpadding=0 cellspacing=0>
<tr valign=top> <td><b><tt>gs -sDEVICE=cdj500 -dBitsPerPixel=24</tt></b>
<td>
<td>for <b><tt>cdjcolor</tt></b>, and
<tr valign=top> <td><b><tt>gs -sDEVICE=cdj500 -dBitsPerPixel=1</tt></b>
<td>
<td>for <b><tt>cdjmono</tt></b>
</table></blockquote>
<h3><a name="HP_paper_size"></a>Default paper size</h3>
<p>
If the preprocessor symbol <b><tt>A4</tt></b> is defined, the default paper
size is ISO A4; otherwise it is U.S. letter size (see about
<a href="Use.htm#Known_paper_sizes">paper sizes</a> in the usage
documentation). You can <a href="Use.htm#Paper_size">specify other paper
sizes</a> on the command line, including A3 for the PaintJet XL and
PaintJet XL300, as also explained in the usage documentation.
<h3><a name="HP_limits"></a>DeskJet physical limits</h3>
<p>
The DeskJet's maximum printing width is 2400 dots, or 8 inches
(20.32cm). The printer manuals say that the maximum recommended printing
height on the page is 10.3 inches (26.16cm), but since this is obviously
not true for A4 paper, and I have been unable to detect any problems in
printing longer page lengths, this would seem to be a rather artificial
restriction.
<p>
All DeskJets have 0.5 inches (1.27cm) of unprintable bottom margin, due to the mechanical
arrangement used to grab the paper. Side margins are approximately 0.25 inches (0.64cm)
for U.S. letter paper, and 0.15 inches (0.38cm) for A4.
<h4><a name="HP_command_line"></a>Printer properties (command-line parameters)</h4>
<p>
Several printer "properties" have been implemented for these printers.
Those available so far are all integer quantities, and thus may be
specified, for instance, like
<blockquote>
<b><tt>gs -dBitsPerPixel=32 -dShingling=1</tt></b> ...
</blockquote>
<p>
which sets the <b><tt>BitsPerPixel</tt></b> parameter to 32 and the
<b><tt>Shingling</tt></b> parameter to 1.
<h4><a name="HP_bpp"></a>Bits per pixel</h4>
<p>
If the preprocessor symbol <b><tt>BITSPERPIXEL</tt></b> is defined as an
integer (see below for the range of allowable values), that number defines
the default bits per pixel (bit depth) for the generic drivers. If the
symbol is undefined, the default is 24 bits per pixel. It is, of course,
still possible to specify the value from the command line as described
below. Note also that the <b><tt>cDeskJet</tt></b>,
<b><tt>cdjcolor</tt></b> and <b><tt>cdjmono</tt></b> drivers are unaffected
by setting this symbol, as their default settings are predefined to be 1, 3
and 24 respectively.
<p>
All of the drivers in <b><tt>gdevcdj.c</tt></b> accept a command line
option to set the <b><tt>BitsPerPixel</tt></b> property. This gives
considerable flexibility in choosing various tradeoffs among speed,
quality, colour, etc. The valid numbers are:
<blockquote><dl compact>
<dt><b>1</b>
<dd>A standard Ghostscript monochrome driver, using black ink (by
installing the separate mono cartridge in the case of the DeskJet 500C, or
automatically for the other printers).
<dt><b>3</b>
<dd>A standard Ghostscript colour driver, using internal dithering. This
is fast to compute and to print, but the clustered dithering can lose some
detail and colour fidelity.
<dt><b>8</b>
<dd>An "error-diffusion" monochrome driver which uses Floyd-Steinberg
dithering to print greyscale images. The patterns are much more randomised
than with the normal clustered dithering, but the data files can be much
larger and somewhat slower to print.
<dt><b>16</b>
<dd>A "cheaper" version of the 24-bit driver, which generates
Floyd-Steinberg colour dithered output using the minimum memory (this may
be helpful when using Ghostscript has not been compiled using a 16-bit
build environment). The quality can be almost as good as the 24-bit
version.
<dt><b>24</b>
<dd>A high-quality colour driver using Floyd-Steinberg dithering for
maximum detail and colour range. However, it is very memory-intensive, and
thus can be slow to compute. It tends to produce rather larger raw data
files, so they can also take longer to print.
<dt><b>32</b>
<dd>Only for the DeskJet 550C, which uses the black cartridge and the
colour cartridge simultaneously (that is, CMYK printing). This printer can
both be faster and give higher quality than the DeskJet 500C, because of
the true black ink. (Note that the 24-bit mode also permits CMYK printing
on this printer, and uses less memory. Any differences between 24-bit and
32-bit should be small.)
</dl></blockquote>
<h4><a name="HP_DeskJet_properties"></a>DeskJet properties</h4>
<blockquote><table cellpadding=0 cellspacing=0>
<tr valign=bottom>
<th align=left>Name
<td>
<th align=left>Type
<td>
<th align=left>
<tr> <td colspan=5><hr>
<tr valign=top> <td><b><tt>BlackCorrect</tt></b>
<td>
<td><b><tt>int</tt></b>
<td>
<td>Colour correction to give better blacks when using the DJ500C in colour mode. For example, the default of 4 reduces the cyan component to 4/5. Range accepted: 0 - 9 (0 = none).
<tr valign=top> <td><b><tt>Shingling</tt></b>
<td>
<td><b><tt>int</tt></b>
<td>
<td>Interlaced, multi-pass printing: 0 = none, 1 = 50%, 2 = 25%, 2 is best and slowest.
<tr valign=top> <td><b><tt>Depletion</tt></b>
<td>
<td><b><tt>int</tt></b>
<td>
<td>"Intelligent" dot-removal: 0 = none, 1 = 25%, 2 = 50%, 1 best for graphics? Use 0 for transparencies.
</table></blockquote>
<h4><a name="HP_PaintJet_properties"></a>PaintJet XL300 / PaintJet XL properties</h4>
<blockquote>
<table cellpadding=0 cellspacing=0>
<tr valign=bottom>
<th align=left>Name
<td>
<th align=left>Type
<td>
<th align=left>
<tr> <td colspan=5><hr>
<tr valign=top> <td><b><tt>PrintQuality</tt></b>
<td>
<td><b><tt>int</tt></b>
<td>
<td>Mechanical print quality: -1 = fast, 0 = normal, 1 = presentation. Fast mode reduces ink usage and uses single-pass operation for some media types. Presentation uses more ink and the maximum number of passes, giving slowest printing for highest quality
<tr valign=top> <td><b><tt>RenderType</tt></b>
<td>
<td><b><tt>int</tt></b>
<td>
<td><dl compact>
<dt><b>0</b><dd>driver does dithering
<dt><b>1</b><dd>snap to primaries
<dt><b>2</b><dd>snap black to white, others to black
<dt><b>3</b><dd>ordered dither
<dt><b>4</b><dd>error diffusion
<dt><b>5</b><dd>monochrome ordered dither
<dt><b>6</b><dd>monochrome error diffusion
<dt><b>7</b><dd>cluster ordered dither
<dt><b>8</b><dd>monochrome cluster ordered dither
<dt><b>9</b><dd>user-defined dither (not supported)
<dt><b>10</b><dd>monochrome user-defined dither ns.
</dl>
</table>
<p>
The PaintJet (non-XL) has no additional properties.
</blockquote>
<h3><a name="HP_gamma"></a>Gamma correction</h3>
<p>
One consequence of using Floyd-Steinberg dithering rather than Ghostscript's
default clustered ordered dither is that it is much more obvious that the
ink dots are rather larger on the page than their nominal 1/180-inch or 1/300-inch
size (clustering the dots tends to minimise this effect). Thus it is often
the case that the printed result is rather too dark. A simple empirical
correction for this may be achieved by preceding the actual PostScript
file to be printed by a short file which effectively sets the gamma for
the device, such as
<blockquote><b><tt>
gs ... gamma.ps colorpic.ps -c quit
</tt></b></blockquote>
<p>
where <b><tt>gamma.ps</tt></b> is
<blockquote>
<pre>%!
/.fixtransfer {
currentcolortransfer 4 {
mark exch
dup type dup /arraytype eq exch /packedarraytype eq or
1 index xcheck and { /exec load } if
0.333 /exp load
] cvx 4 1 roll
} repeat setcolortransfer
} bind odef
.fixtransfer
/setpagedevice { setpagedevice .fixtransfer } bind odef</pre>
</blockquote>
<p>
This does the gamma correction <b><em>after</em></b> whatever correction
the device might be doing already. To do the correction
<b><em>before</em></b> the current correction,
<blockquote>
<pre>%!
/.fixtransfer {
currentcolortransfer 4 {
mark 0.333 /exp load 4 -1 roll
dup type dup /arraytype eq exch /packedarraytype eq or
1 index xcheck and { /exec load } if
] cvx 4 1 roll
} repeat setcolortransfer
} bind odef
.fixtransfer
/setpagedevice { setpagedevice .fixtransfer } bind odef</pre>
</blockquote>
<p>
This example sets the gamma for R, G, and B to 3, which seems to work
reasonably well in practice.
<h3><a name="HP_resolution_enhance"></a>HP's resolution-enhanced mode for Inkjet printers</h3>
<p>
This feature is available on HP's more recent inkjet printers, including
the DeskJet 520 (mono), 540 (mono or colour) and 560C (mono and colour).
The colour and monochrome drivers for the HP DeskJet 550c are (probably)
the best you will get for use with Ghostscript, for the following reasons.
<p>
These printers do not offer true 600×300dpi resolution. Those that
print in colour are strictly 300×300dpi in colour mode, while in mono
mode there is a pseudo 600×300dpi mode with the restriction that you
can't print two adjacent dots. In effect what you have is 600dpi dot
positioning, but on average you don't get more dots per line. This
provides the possibility, for instance, to have sharper character outlines,
because you can place dots on the edges nearer to their ideal positions.
This is why it is worth doing.
<p>
However, HP will not support user-level programming of this
resolution-enhanced mode, one reason being that (I understand) all the dot
spacing has to be done by the driver, and if you get it wrong, you can
actually damage the print head.
<p>
To summarise, you may lose a smidgin of (potential) text clarity using the
550c drivers (<b><tt>cdj550</tt></b>, <b><tt>cdjcolor</tt></b>,
<b><tt>cdjmono</tt></b> etc.), but other than that, they are the ones for
the job.
<h3><a name="HP_tips"></a>General tips</h3>
<p>
For all the printers above, the choice of paper is critically important to
the final results. The printer manuals suggest type of paper, but in
general, smoother, less fibrous types give better results. In particular,
the special ink-jet paper can make a big difference: colours are brighter,
but most importantly, there is almost no colour bleed, even with adjacent
areas of very heavy inking. Similarly the special coated transparencies
also work well (and ordinary transparencies do not work at all!).
<p>
The Unix procedure <a href="Unix-lpr.htm"><b><tt>unix-lpr.sh</tt></b></a>
provides one example of setting up a multi-option colour PostScript
<b><tt>lpr</tt></b> queue on Unix systems, and includes the ability to
choose a range of different colour options and printer accounting and error
logging.
<p>
<b>Caveat emptor!</b> It is not always easy for me to test all of these
drivers, as the only colour printer I have here is the DeskJet 500C. I rely
on others to test drivers for the additional machines and report their
findings back to me.
<hr>
<h2><a name="BJC_8200"></a>Canon BJC-8200 printer</h2>
<p>
This section was contributed by the author of the <b><tt>uniprint</tt></b>
configuration files for the Canon BJC-8200, Stephan C. Buchert <<a
href="mailto:scb@stelab.nagoya-u.ac.jp">scb@stelab.nagoya-u.ac.jp</a>>.
These files also handle the Japanese Canon F850 printer.
<p>
Warning: Usage of this program is neither supported nor endorsed by
the Canon corporation. Please see the Ghostscript <a
href="Public.htm">license</a> regarding warranty.
<h3>Introduction</h3>
<p>
The Canon Bubble Jet printer BJC-8200 is designed for printing digital
photos and halftone images. Software drivers for Windows 95-2000 and Mac are
usually included and can be downloaded from the Canon web sites like
<a href="http://consumer.usa.canon.com/bjc/bjc8200/">http://consumer.usa.canon.com/bjc/bjc8200/</a>
for the US market. If these drivers cannot be used for some reason, then at
present Ghostscript is probably the alternative giving the best results.
<p>
The BJC-8200 has features not found among the specs of earlier bubble jet
models (except the even more advanced BJC-8500) and is advertised to offer:
<ol>
<li>microfine droplet technology;
<li>support for printing on a new type of paper, Photo Paper Pro;
<li>a printhead capable of printing up to 1200 DpI;
<li>individual ink tanks for 6 colors;
<li>an internal status monitor reporting low ink back to a driver;
<li>an optional color scanner cartridge for up to 600 DpI resolution.
</ol>
<p>
Access to features 5 and 6 requires use of the original Canon drivers for
the foreseeable future. This README is about getting the printer features
1-3 working with Ghostscript. No (re)compilation of Ghostscript is normally
required.
<p>
Ghostscript comes with a relatively highly configurable driver, called
<a href="#Uniprint">uniprint</a>, for printers which understand raster
images in various propriety formats. Most options for this driver are
usually organized into files having the suffix ".upp." Ghostscript
versions >= 5.10 (or even earlier) include such uniprint control files
for the Canon BJC-610. They work also well for some other Canon Bubble
Jet models, for example for my BJC-35vII. But when using them for a
BJC-8200 the result is unsatisfactory.
<h3>The uniprint control files for the BJC-8200</h3>
<p>
After some experimenting with the options for uniprint I have obtained quite
satisfactory prints with my printer(*). This distribution includes six new
uniprint control files:
<ul>
<li>bj8pp12f.upp
<li>bj8hg12f.upp
<li>bj8gc12f.upp
<li>bj8oh06n.upp
<li>bj8ts06n.upp
<li>bj8pa06n.upp
</ul>
<p>
They are included in Ghostscript >=6.21. For older versions you can put
them anywhere in the Ghostscript search path (type "gs -h" to see the
path), but should perhaps add the files to the directory with the
other *.upp files. This is "/usr/share/ghostscript/gs6.01/lib" in my
RedHat 6.1 Linux box with Aladdin Ghostscript 6.01.
<p>
Here is an explanation of my file name convention: the prefix "bj8" should
perhaps be used for the Canon BJC-8200 and compatible (like the Japanese
F850 and perhaps the non-Japanese BJC-8500) models. The next two letters
indicate the print media:
<ul>
<li>pp "Photo Paper Pro"
<li>hg "High Gloss Photo Film"
<li>gc "Glossy Photo Cards"
<li>oh "OHP transparencies"
<li>ts "T-shirt transfer"
<li>pa "Plain Paper"
</ul>
<p>
The numbers at positions 6 and 7 indicate the resolution
<ul>
<li>12 1200x1200 DpIxDpI
<li>06 600x600 DpIxDpI
</ul>
<p>
The last letter stands for a quality factor that effects also the print
speed (presumably related to the number of passes that the printhead makes).
<ul>
<li>f highest quality
<li>n normal quality
</ul>
<p>
Printing a postcard size (~10x15 cm^2) image at 1200x1200 DpI^2 takes about
3 minutes. The output of Ghostscript is then typically 4-5 MByte. The
bootleneck seems to be the transfer of the raster image in run-length
encoded Canon format to the printer (via the parallel port on my system) or
the printer's speed, not Ghostscript or the uniprint renderer.
<h3>Further Optimization for the Canon BJC-8200</h3>
So far I have only experimented with the printer initialization code at the
beginning of each page (-dupBeginPageCommand) and the resolution (-r). Other
options, particularly the transfer arrays (-dupBlackTransfer,
-dupCyanTransfer, -dupMagentaTransfer, -dupYellowTransfer) and the margins
(-dupMargins) were simply copied from the files for the BJC-610, but they
may need to be changed for optimized performance.
<p>
Here is information useful for changing or adding uniprint control files for
the BJC-8200:
<p>
In "-dupBeginPageCommand=..." use the line
<blockquote>
1b28 64 0400 04b0 04b0
</blockquote>
<p>
for 1200x1200 resolution, and
<blockquote>
1b28 64 0400 0258 0258
</blockquote>
<p>
for 600x600. The "-r" option in the control file must of course match this
line. Other resolutions might work as well, but I didn't try.
<p>
Crucial are the numbers in the lines like
<blockquote><pre>
1b28 63 0300 3005 04
^ ^
Plain Paper 0 4 Highest quality
OHP transparency 2 .
T-shirt transfer 3 .
Glossy Photo Film 5 .
High Gloss Paper 6 0 Lowest quality
Photo Paper Pro 9
</pre></blockquote>
<h3>Outlook</h3>
<p>
Presently uniprint can use the black (K), cyan (C), magenta (M), and
yellow (Y) colors in the BJC-8200. The unused colors are photo (or
light) cyan (c) and magenta (m). Also the Canon driver seems to use
only CMYK, for example when printing on Photo Paper Pro in "Camera" or
"SuperPhoto" mode. These modes supposedly produce prints of the best
quality that the Canon driver can offer. Other modes of Canon driver
do use up to all six color cartridges (CMYKcm). Therefore expanding
uniprint's capabilities for six colors would be interesting, but it may
not increase the output quality of 6-color printers such as the
BJC-8200 drastically.
<p>
More control files for uniprint could be added in order to offer more
versatility for controlling the BJC-8200 within a Ghostscript
installation. The number of possible combinations for media type, resolution
and print quality factor is very large, many combinations would not make
much sense, many might be used here and there, but relatively rarely. The
user would have to remember a name for each combination that is used.
<p>
A better way would be to let the user patch optionally a user owned or
system wide uniprint control file before each print via some print
tool. This is similar to the approach taken by Canon with their driver for
Windows. Similarly a uniprint tool could also incorporate other functions
such as printing test and demo pages and the low ink warning once the
protocol for this is known. Clearly it would be difficult to code such a
uniprint tool for all the platforms where Ghostscript is running.
<h3>Usage on RedHat Linux</h3>
<p>
In order to install a BJC-8200 printer on a RedHat Linux system with
RedHat's printtool, you need also to insert with a text editor the contents
of the file <b><tt>bj8.rpd</tt></b> into the RedHat printer database
<b><tt>/usr/lib/rhs/rhs-printfilters/printerdb</tt></b>. Insert it most
appropriately after the section
<blockquote><pre>
StartEntry: U_CanonBJC610
.
.
.
EndEntry
< --- insert here "bj8.rpd" from this distribution:
< --- StartEntry: U_CanonBJC8200
.
.
.
</pre></blockquote>
<h3>Contacting the Author</h3>
<p>
E-mail address: <<a
href="mailto:scb@stelab.nagoya-u.ac.jp">scb@stelab.nagoya-u.ac.jp</a>>
<p>
Footnotes:
<p>
(*) Actually I have a F850, not a BJC-8200. That model is sold for the
Japanese market only. The specs and also the external look are the
same as those of the BJC-8200 models for the American and European
markets. I expect that the raster image mode which is used exclusively
by Ghostscript is entirely compatible for both models.
<p>
Stephan C. Buchert
<hr>
<h2><a name="BJC"></a>Other Canon BubbleJet (BJC) printers</h2>
<p>
This section was contributed by the author of the drivers, Yves Arrouye
(<<a href="mailto:yves.arrouye@usa.net">yves.arrouye@usa.net</a>>, but
please do not send questions to him: he no longer maintains these drivers.)
The drivers handle Canon BJC-600, BJC-4xxx, BJC-70, Stylewriter 2x00, and
BJC-800 printers.
<h3><a name="BJC_history"></a>History</h3>
<p>
The BJC-600 driver was written in the first place by Yoshio Kuniyoshi and
later modified by Yves Arrouye. We tried to make it evolve synchronously,
though Yoshio cannot be reached since a long time ago. The drivers are
based on code for the HP printers by George Cameron (in fact, they are in
the same file!), so he's the first person to thank.
<p>
The 2.00 version of the drivers was a complete rewrite of the driver
(arguments, optimization, colour handling, in short: everything!) by Yves
Arrouye. That release was also the first one to be able to use the full
width of an A3 paper size. PostScript Printer Description (PPD) files for
the drivers were released with version 2.15. They are incomplete,
but they can be used to drive the printers' main features.
<h3><a name="BJC_build"></a>Configuring and building the BJC drivers</h3>
<h4><a name="BJC_defaults"></a>Modify values in
<b><tt>gdevbjc.h</tt></b></h4>
<p>
Configure the drivers by modifying the default values in the file
<b><tt>gdevbjc.h</tt></b> or on the compilation line. If you don't do
that, the drivers use reasonable defaults that make them work "as
expected". All default values shown here are defined in that file.
<h4><a name="BJC_CMYK_RGB"></a>CMYK-to-RGB color conversion</h4>
<p>
By default, the drivers use the same algorithm as Ghostscript to convert
CMYK colors to RGB. If you prefer to use Adobe formulas, define
<b><tt>USE_ADOBE_CMYK_RGB</tt></b> when compiling. (See the top of the
file <b><tt>gdevcdj.c</tt></b> to see the difference between the two.)
<h4><a name="BJC_vertical_centering"></a>Vertical centering of the
printable area</h4>
<p>
The drivers center the imageable area horizontally but not vertically, so
that what can be printed does use the most of the output media. If you
define <b><tt>BJC_DEFAULT_CENTEREDAREA</tt></b> when compiling, then the
top and bottom margins will be the same, resulting in a (smaller)
vertically centered imageable area also.
<h4><a name="BJC_margins"></a>Page margins</h4>
<p>
If you define <b><tt>USE_RECOMMENDED_MARGINS</tt></b>, then the top and
bottom margins will be the same (that is,
<b><tt>BJC_DEFAULT_CENTEREDAREA</tt></b> will be defined for you) and the
margins will be the 12.4mm recommended by Canon. Since margins are
complicated (because one must rely on the mechanical precision of the
printer), the drivers do something about the bottom margin: by default the
bottom margin is 9.54mm for the BJC-600 driver and 7mm for the BJC-800. If
you define <b><tt>USE_TIGHT_MARGINS</tt></b>, then the bottom margin is 7mm
for both drivers (but I never managed to get my own BJC-600 to print a line
on this low bound, hence the larger default). Regardless of the presence
of this definition, <b><tt>USE_FIXED_MARGINS</tt></b> will not allow the
BJC-800 to use the lower 7mm bottom margin, so if you have a problem with
the bottom margin on a BJC-800, just define that (without defining
<b><tt>USE_TIGHT_MARGINS</tt></b>, of course).
<p>
A quick way to be sure the margins you selected is to print a file whose
contents are:
<blockquote><b><tt>
%!<br>
clippath stroke showpage
</tt></b></blockquote>
<p>
If the margins are okay, you will get a rectangle visibly surrounding
the printable area. If they're not correct, one or more of the sides will
be either incomplete or completely unprinted.
<h4><a name="BJC_compile"></a>Makefile and compilation</h4>
<p>
Make sure the <b><tt>bjc600</tt></b> or <b><tt>bjc800</tt></b> devices are
in <a href="Make.htm#Features_and_devices"><b><tt>DEVICE_DEVS</tt></b> in
the makefile</a>; that is, look in the makefile for your platform and add
them if necessary -- they may already be there. As of Ghostscript 5.10,
for instance, one makefile has
<blockquote><b><tt>
DEVICE_DEVS6=bj10e.dev bj200.dev bjc600.dev bjc800.dev
</tt></b></blockquote>
<h3><a name="BJC_usage"></a>Use of the drivers</h3>
<p>
There are two drivers here. The "<b><tt>bjc600</tt></b>" one supports the BJC-600 and
BJC-4xxx (maybe the BJC-70 as well) and the "<b><tt>bjc800</tt></b>" one supports the
BJC-800 series. Remarks here that apply to both drivers use the name
"bjc".
<h4><a name="BJC_options"></a>Supported Options and Defaults</h4>
<p>
Note: "options", "properties", and "parameters" designate the same thing:
device parameters that you can change.
<p>
Giving an option an incorrect value causes an error. Unless stated
otherwise, this error will be a rangecheckerror. Options may be set from
the Ghostscript command line (using the <b><tt>-d</tt></b> and
<b><tt>-s</tt></b> switches or other predetermined switches if they have an
effect on the driver) or using the PostScript Level 2
<b><tt>setpagedevice</tt></b> operator if Ghostscript has been compiled
with the <b><tt>level2</tt></b> or <b><tt>level3</tt></b> device (which it should
<b><tt>;-)</tt></b>). There are <b>no</b> special-purpose operators such as
one was able to find in Level 1 printers.
<p>
The bjc uses 24 bits per pixel by default (unless you change the value of
<b><tt>BJC_BITSPERPIXEL</tt></b>), corresponding to CMYK printing.
Supported modes are 1 bpp and 4 bpp (gray levels), 8 bpp, 16 bpp, 24 bpp
and 32 bpp (colours). Colours are preferably stored in the CMYK model
(which means, for example, that with 16 bpp there are only 16 different
shades of each color) but it is possible to store them as RGB color for
some depths. Some modes do Floyd-Steinberg dithering and some don't, but
use the default Ghostscript halftoning (in fact, when halftoning is used,
dithering takes also place but because of the low point density it is
usually not efficient, and thus invisible).
<blockquote><table cellpadding=0 cellspacing=0>
<tr><th colspan=5 bgcolor="#CCCC00"><hr><font size="+1">Descriptions of printing modes by bpp and <b><tt>Colors</tt></b></font><hr>
<tr valign=bottom>
<th align=left>bpp
<td>
<th align=left><b><tt>Colors</tt></b>
<td>
<th align=left>Mode
<tr> <td colspan=5><hr>
<tr valign=top> <td>32
<td>
<td align=center>4
<td>
<td>CMYK colour printing, Floyd-Steinberg dithering
<tr valign=top> <td>24
<td>
<td align=center>4
<td>
<td>The same. (But each primary colour is stored on 6 bits instead of 8.)
<tr valign=top> <td>24
<td>
<td align=center>3
<td>
<td>RGB colour printing, Floyd-Steinberg dithering. This mode does
<b><tt>not</tt></b> use the black cartridge (that's why it
exists, for when you don't want to use it <b><tt>;-)</tt></b>).
Each primary colour is stored in 8 bits as in the 32/4 mode,
but black generation and under-color removal are done on the
driver side and not by Ghostscript, so you have no control over
it. (This mode is no longer supported in this driver.)
<tr valign=top> <td>16
<td>
<td align=center>4
<td>
<td>CMYK colour printing, halftoned by Ghostscript. F-S dithering
is still visible here (but the halftone patterns are visible
too!).
<tr valign=top> <td>8
<td>
<td align=center>4
<td>
<td>The same. (But each primary colour is stored in 2 bits instead of 4.)
<tr valign=top> <td>8
<td>
<td align=center>3
<td>
<td>RGB colour printing. This mode is not intended for use. What I
mean is that it should be used only if you want to use custom
halftone screens <b>and</b> the halftoning is broken using the
8/4 mode (some versions of Ghostscript have this problem).
<tr valign=top> <td>8
<td>
<td align=center>1
<td>
<td>Gray-level printing, Floyd-Steinberg dithering
<tr valign=top> <td>1
<td>
<td align=center>1
<td>
<td>Gray-level printing halftoned by Ghostscript
</table></blockquote>
<p>
These modes are selected using the <b><tt>BitsPerPixel</tt></b> <b>and</b>
<b><tt>Colors</tt></b> integer options (either from the command line or in
a PostScript program using <b><tt>setpagedevice</tt></b>). See below.
<p>
A note about darkness of what is printed: Canon printers do print dark,
really. And the Floyd-Steinberg dithering may eventually darken your image
too. So you may need to apply gamma correction by calling Ghostscript as in
<blockquote><b><tt>
gs -sDEVICE=bjc600 gamma.ps myfile.ps
</tt></b></blockquote>
<p>
where <b><tt>gamma.ps</tt></b> changes the gamma correction (here to 3 for
all colors); 0.45 gives me good results, but your mileage may vary. The
bigger the value the lighter the output:
<blockquote><b><tt>
{ 0.45 exp } dup dup currenttransfer setcolortransfer
</tt></b></blockquote>
<p>
The drivers support printing at 90dpi, 180dpi and 360dpi. Horizontal and
vertical resolutions must be the same or a limitcheck error will happen. A
rangecheck will happen too if the resolution is not
90 ×2^<small><sup><b>N</b></sup></small>. If the driver
is compiled with <b><tt>-DBJC_STRICT</tt></b> a rangecheck also happens if
the resolution is not one of those supported. This is not the case, as we
expect that there may be a 720dpi bjc some day.
<p>
Here are the various options supported by the bjc drivers, along with
their types, supported values, effects, and usage:
<dl>
<dt><b><tt>BitsPerPixel</tt></b> (int)
<dd>Choose the depth of the page. Valid values are 1, 8, 16, 24 (the
default) and 32.
<p>
Note that when this is set for the first time, the <b><tt>Colors</tt></b>
property is automatically adjusted unless it is also specified. The table
here shows the corresponding color models and the rendering method visible:
"GS" for Ghostscript halftoning and "F-S" for Floyd-Steinberg dithering.
When both are present it means that the dithering of halftones is visible.
Default choices are indicated by asterisk "*".
<blockquote><table cellpadding=0 cellspacing=0>
<tr><th colspan=9 bgcolor="#CCCC00"><hr><font size="+1">Valid <b><tt>Colors</tt></b> values for<br>allowed <b><tt>BitsPerPixel</tt></b> values
</font><hr>
<tr valign=bottom>
<th align=left>bpp
<td>
<th align=left><b><tt>Colors</tt></b>
<td>
<th align=left>
<td>
<th align=left>Color model
<td>
<th align=left>Dithering
<tr> <td colspan=9><hr>
<tr valign=top> <td>32
<td>
<td align=center>4
<td>
<td>
<td align=center>
<td>CMYK
<td>
<td>F-S
<tr valign=top> <td>24
<td>
<td align=center>4
<td>
<td><b>*</b>
<td align=center>
<td>CMYK
<td>
<td>F-S
<tr valign=top> <td>
<td>
<td align=center>3
<td>
<td>
<td align=center>
<td>RGB
<td>
<td>F-S
<tr valign=top> <td>16
<td>
<td align=center>4
<td>
<td>
<td align=center>
<td>CMYK
<td>
<td>GS, F-S
<tr valign=top> <td>8
<td>
<td align=center>4
<td>
<td><b>*</b>
<td align=center>
<td>CMYK
<td>
<td>GS
<tr valign=top> <td>
<td>
<td align=center>3
<td>
<td>
<td align=center>
<td>RGB
<td>
<td>GS
<tr valign=top> <td>
<td>
<td align=center>1
<td>
<td>
<td align=center>
<td>K (CMYK)
<td>
<td>F-S
<tr valign=top> <td>1
<td>
<td align=center>1
<td>
<td><b>*</b>
<td align=center>
<td>K (CMYK)
<td>
<td>GS
</table></blockquote>
<p>Also note that automagical change of one parameter depending on the
other one does not work in a <b><tt>setpagedevice</tt></b> call. This
means that if you want to change <b><tt>BitsPerPixel</tt></b> to a value
whose valid <b><tt>Colors</tt></b> values do not include the actual
<b><tt>Colors</tt></b> value, you must change <b><tt>Colors</tt></b> too.
</dl>
<dl>
<dt><b><tt>Colors</tt></b> (int)
<dd>Choose the number of color components from among 1, 3 and 4 (the
default). This setting cannot be used in a PostScript program, only on
Ghostscript's command line. See <b><tt>ProcessColorModel</tt></b> below
for what to use to change the number of colors with PostScript code.
<p>
Note that setting this property does limit the choices of
<b><tt>BitsPerPixel</tt></b>. As for the previous property, its first
setting may induce a setting of the "other value"
(<b><tt>BitsPerPixel</tt></b> here). The table here indicates valid
combinations with "V", default values with asterisk "*".
<blockquote><table cellpadding=0 cellspacing=0>
<tr><th colspan=13 bgcolor="#CCCC00"><hr><font size="+1">Valid <b><tt>BitsPerPixel</tt></b> values<br>for allowed <b><tt>Colors</tt></b> values</font><hr>
<tr valign=top> <td>
<td>
<td>
<td>
<th align=left colspan=9><b><tt>BitsPerPixel</tt></b> OK values<hr>
<tr valign=top> <th>Colors
<td>
<th>Type
<td>
<td>32
<td>
<td>24
<td>
<td>16
<td>
<td>8
<td>
<td>1
<tr> <td colspan=13><hr>
<tr valign=top> <td>4
<td>
<td>CMYK
<td>
<td><b>V</b>
<td>
<td><b>*</b>
<td>
<td><b>V</b>
<td>
<td><b>V</b>
<td>
<td>
<tr valign=top> <td>3
<td>
<td>RGB
<td>
<td>
<td>
<td><b>*</b>
<td>
<td>
<td>
<td><b>V</b>
<td>
<td>
<tr valign=top> <td>1
<td>
<td>K
<td>
<td>
<td>
<td>
<td>
<td>
<td>
<td><b>V</b>
<td>
<td><b>*</b>
</table></blockquote>
<p>Also note that automagical change of one parameter depending on the
other one does not work in a <b><tt>setpagedevice</tt></b> call. This
means that if you want to change <b><tt>Colors</tt></b> to a value whose
valid <b><tt>BitsPerPixel</tt></b> values don't include the actual
<b><tt>BitsPerPixel</tt></b> value, you must change
<b><tt>BitsPerPixel</tt></b> too.
</dl>
<dl>
<dt><b><tt>ProcessColorModel</tt></b> (symbol)
<dd>A symbol taken from <b><tt>/DeviceGray</tt></b>,
<b><tt>/DeviceRGB</tt></b> or <b><tt>/DeviceCMYK</tt></b> which can be used
to select 1, 3 or 4 colors respectively. Note that this parameter takes
precedence over <b><tt>Colors</tt></b>, and that both affect the same
variable of the driver. (See <b><tt>Colors</tt></b> above for values
combined with <b><tt>BitsPerPixel</tt></b>.)
</dl>
<dl>
<dt><b><tt>HWResolution</tt></b> (floats array)
<dd>An array of two floats giving the horizontal and vertical resolution in
dots per inch from among 90, 180 and 360 (the default). Both values must
be the same. On the Ghostscript command line, the resolution may be
changed with the <a href="Use.htm#Resolution_switch"><b><tt>-r</tt></b>
switch</a>.
</dl>
<dl>
<dt><b><tt>ManualFeed</tt></b> (bool)
<dd>Indicate that the sheets won't be fed automatically by the printer,
<b><tt>false</tt></b> by default. (Not meaningful on the BJC-600, I fear.)
</dl>
<dl>
<dt><b><tt>MediaType</tt></b> (string)
<dd>The media to print on, chosen from among "<b><tt>PlainPaper</tt></b>",
"<b><tt>CoatedPaper</tt></b>", "<b><tt>TransparencyFilm</tt></b>",
"<b><tt>Envelope</tt></b>", "<b><tt>Card</tt></b>" and
"<b><tt>Other</tt></b>". Default is "<b><tt>PlainPaper</tt></b>". For
"<b><tt>Envelope</tt></b>", "<b><tt>Card</tt></b>" or
"<b><tt>Other</tt></b>" the driver puts the printer into thick mode
automatically regardless of the actual media weight.
</dl>
<dl>
<dt><b><tt>MediaWeight</tt></b> (int or null)
<dd>The weight of the media in grams per square meter. Null (the default)
indicates that the weight is of no importance. If the specified media
weight is greater than 105 (that is, the value of the compilation default
<b><tt>BJC</tt></b>???<b><tt>_MEDIAWEIGHT_THICKLIMIT</tt></b>) then the
printer will be set to use thick paper.
</dl>
<dl>
<dt><b><tt>PrintQuality</tt></b> (string)
<dd>The quality of printing.
<table cellpadding=0 cellspacing=0>
<tr valign=bottom>
<th align=left>Value
<td>
<th align=left><b><tt>bjc600</tt></b>
<td>
<th align=left><b><tt>bjc800</tt></b>
<td>
<th align=left>
<tr> <td colspan=7><hr>
<tr valign=top> <td><b><tt>Low</tt></b>
<td>
<td>
<td>
<td align=center><b>X</b>
<td>
<td>Has the effect of making only two printing passes instead of four, so should be twice the speed; known as "CN" (Color Normal) mode
<tr valign=top> <td><b><tt>Draft</tt></b>
<td>
<td align=center><b>X</b>
<td>
<td align=center><b>X</b>
<td>
<td>Unlights the "HQ" light on a BJC-600
<tr valign=top> <td><b><tt>Normal</tt></b>
<td>
<td align=center><b>X</b>
<td>
<td align=center><b>X</b>
<td>
<td>Default for both drivers; lights the "HQ" light on a BJC-600
<tr valign=top> <td><b><tt>High</tt></b>
<td>
<td align=center><b>X</b>
<td>
<td align=center><b>X</b>
<td>
<td>Means 200% black and 100% CMY; lights the "Bk+" light on a BJC-600
</table>
</dl>
<dl>
<dt><b><tt>DitheringType</tt></b> (string)
<dd>Dithering algorithm from between "<b><tt>Floyd-Steinberg</tt></b>" and
"<b><tt>None</tt></b>". "<b><tt>None</tt></b>" is the default for 1/1 print
mode, "<b><tt>Floyd-Steinberg</tt></b>" for other modes. At the moment
this parameter is read-only, though no error is generated if one tries to
change it. This parameter is not of much value at the moment and is here
mainly to reserve the name for future addition of dithering algorithms.
</dl>
<dl>
<dt><b><tt>PrintColors</tt></b> (int)
<dd>Mask for printing color. If 0, use black for any color; otherwise the
value must be the sum of any of 1 (cyan), 2 (magenta), 4 (yellow) and 8
(black), indicating which colors will be used for printing. When printing
colour, only colours specified will be printed (this means that some planes
will be missing if a color's value above is omitted). When printing grays,
black is used if it is present in the <b><tt>PrintColors</tt></b>;
otherwise, the image is printed by superimposing each requested color.
</dl>
<dl>
<dt><b><tt>MonochromePrint</tt></b> (bool)
<dd><b>For <tt>bjc600</tt> only</b>, <b><tt>false</tt></b> by default.
Substitute black for Cyan, Magenta and Yellow when printing -- useful, for
example, to get some monochrome output of a dithered printing This is a
hardware mechanism as opposed to the previous software one. I think that
using this or setting <b><tt>PrintColors</tt></b> to 0 will give the same
results.
</dl>
<p>
Note that the <b><tt>MediaType</tt></b> and <b><tt>ThickMedia</tt></b>
options will be replaced by the use of the device
<b><tt>InputAttributes</tt></b> and <b><tt>OutputAttributes</tt></b> as
soon as possible. Please note too that the print mode may be reset at the
start of printing, not at the end. This is the expected behaviour. If you
need to reset the printer to its default state, simply print a file that
does just a <b><tt>showpage</tt></b>.
<h4><a name="BJC_device_info"></a>Device information</h4>
<p>
Here is other information published by the driver that you will find
in the <b><tt>deviceinfo</tt></b> dictionary.
<dl>
<dt><b><tt>OutputFaceUp</tt></b> (bool)
<dd>This has the boolean value <b><tt>true</tt></b>, indicating that the
sheets are stacked face up.
</dl>
<dl>
<dt><b><tt>Version</tt></b> (float)
<dd>In the form <b>M.</b><em>mm</em>pp, where <b>M</b> is the major
version, <em>mm</em> the bjc driver's minor version, and pp the specific
driver minor version (that is, <b><tt>M.</tt></b><em>mm</em> will always be
the same for the <b><tt>bjc600</tt></b> and <b><tt>bjc800</tt></b>
drivers).
</dl>
<dl>
<dt><b><tt>VersionString</tt></b> (string)
<dd> A string showing the driver version and other indications. At the
moment, things like "a" or "b" may follow the version to indicate alpha or
beta versions. The date of the last change to this version is given in the
form MM/DD/YY (no, it won't adapt to your locale).
</dl>
<h4><a name="BJC_HW_margins"></a>Hardware margins</h4>
<p>
The BJC printers have top and bottom hardware margins of 3mm and 7.1mm
respectively (Canon says 7mm, but this is unusable because of the rounding
of paper sizes to PostScript points). The left margin is 3.4mm for A4 and
smaller paper sizes, 6.4mm for U.S. paper sizes, envelopes and cards. It
is 4.0mm for A3 paper on the BJC-800.
<p>
The maximum printing width of a BJC-600 printer is 203mm. The maximum
printing width of a BJC-800 printer is 289mm on A3 paper, 203mm on
U.S. letter and ISO A4 paper.
<h4><a name="BJC_PPD"></a>PostScript printer description (PPD) files</h4>
<p>
The files <b><tt>CBJC600.PPD</tt></b> and <b><tt>CBJC800.PPD</tt></b> (whose
long names are, respectively, <b><tt>Canon_BubbleJetColor_600.ppd</tt></b>
and <b><tt>Canon_BubbleJetColor_800.ppd</tt></b>) are PPD files to drive the
features of the <b><tt>bjc600</tt></b> and <b><tt>bjc800</tt></b> drivers.
They can be used, for example, on NextStep systems (presumably on OpenStep
systems too) and on Unix systems with Adobe's TranScript and
<b><tt>pslpr</tt></b> (not tested). The files are not complete at the
moment. Please note that NextStep's printing interface does not
correctly enforce constraints specified in these files (in UIConstraints
descriptions): you must force yourself to use valid combinations of
options.
<h4><a name="BJC_PPD_custom"></a>Customizing the PPD files</h4>
<p>
By default the PPD files are set for U.S. letter size paper, and they use a
normalized transfer function. If you choose to use A4 printing by default,
you must replace "<b><tt>Letter</tt></b>" with "<b><tt>A4</tt></b>" in
these (noncontiguous) lines:
<blockquote>
[...]<br>
<b><tt>*DefaultPageSize: Letter<br></tt></b>
[...]<br>
<b><tt>*DefaultRegion: Letter<br></tt></b>
[...]<br>
<b><tt>*DefaultImageableArea: Letter</tt></b><br>
[...]<br>
</blockquote>
<p>
Some versions of Ghostscript have problems with normalized colors, which
makes them add magenta in gray levels. If you experience this problem,
in the PPD file replace the line
<blockquote><b><tt>
*DefaultTransfer: Normalized
</tt></b></blockquote>
<p>
with the alternate line
<blockquote><b><tt>
*DefaultTransfer: Null
</tt></b></blockquote>
<p>
The "thick media" option is implemented by choosing a value of 120 or 80
(for thick and thin media respectively) for the <b><tt>MediaWeight</tt></b>
feature of the drivers. If you ever change the threshold for thick media
in the driver code, you may need to change the values in the PPD files too.
<p>
All customization should be done using the "<b><tt>*Include:</tt></b>"
feature of PPD files so that your local changes will be retained if you
update the PPD files.
<h3><a name="BJC_bugs"></a>How to report problems</h3>
<p>
Yves Arrouye no longer maintains this driver, and will not answer questions
about it. If you are posting a question about it in a public form, please
be as descriptive as possible, and please send information that can be used
to reproduce the problem. Don't forget to say which driver you use, and in
what version. Version information can be found in the source code of the
driver or by issuing the following command in a shell:
<blockquote><b><tt>
echo "currentpagedevice /VersionString get ==" | gs -q -sDEVICE=bjc600 -
</tt></b></blockquote>
<h3><a name="BJC_acks"></a>Acknowledgements</h3>
<p>
I am particularly grateful to Yoshio Kuniyoshi <<a
href="mailto:yoshio@nak.math.keio.ac.jp">yoshio@nak.math.keio.ac.jp</a>>
without whom I'd never make these drivers, and also to L. Peter Deutsch,
who answered all my (often silly) questions about Ghostscript's driver
interface.
<p>
Thanks also to the people who volunteered to beta-test the v2.x BJC
drivers: David Gaudine
<<a href="mailto:david@donald.concordia.ca">david@donald.concordia.ca</a>>,
Robert M. Kenney <<a href="mailto:rmk@unh.edu">rmk@unh.edu</a>>,
James McPherson
<<a href="mailto:someone@erols.com">someone@erols.com</a>>
and Ian Thurlbeck
<<a href="mailto:ian@stams.strath.ac.uk">ian@stams.strath.ac.uk</a>>
(listed alphabetically) were particularly helpful by discovering bugs and
helping find out exact paper margins on printers I don't have access to.
<p>
And many thanks to Klaus-Gunther Hess
<<a href="mailto:ghess@elmos.de">ghess@elmos.de</a>> for looking
at the dithering code and devising a good CMYK dithering algorithm for the
Epson Stylus Color, which I then adapted to the code of these drivers.
<hr>
<h2><a name="STC_epson_stylus"></a>Epson Stylus color printer (see also <b><tt>uniprint</tt></b>)</h2>
<p>
This section was contributed by Gunther Hess
<<a href="mailto:ghess@elmos.de">ghess@elmos.de</a>>, who also wrote
<b><tt>uniprint</tt></b>, a later set of drivers. You should probably see
the section on <a href="#Uniprint"><b><tt>uniprint</tt></b></a> for whether
it might be better for your uses than this driver.
<h3><a name="STC_usage"></a>Usage</h3>
<p>
This driver is selected with "<b><tt>-sDEVICE=stcolor</tt></b>", producing
output for an Epson Stylus Color at 360dpi resolution by default. But it
can do much more with this printer, and with significantly better quality,
than with the default mode; and it can also produce code for monochrome
versions of the printer. This can be achieved via either command-line
options or Ghostscript input. For convenience a PostScript file is
supplied for use as an initial input file. Try the following command:
<blockquote>
<b><tt>gs -sDEVICE=stcolor -r</tt></b><b>{Xdpi}</b><b><tt>x</tt></b><b>{Ydpi}</b><b><tt> stcolor.ps</tt></b> <b>{YourFile.ps}</b>
</blockquote>
<p>
where <b>{Xdpi}</b> is one of 180, 360, or 720 and <b>{Ydpi}</b> is one of
90, 180, 360, or 720. The result should be significantly better. You may
use <b><tt>stcolor.ps</tt></b> with other devices too, but I do not
recommend this, since it does nothing then. <b><tt>stcolor.ps</tt></b>
should be available with binary distributions and should reside in the same
directory as other Ghostscript initialization files or in the same
directory as the files to be printed. Thus if Ghostscript is part of your
printer-spooler, you can insert
<blockquote><b><tt>
(stcolor.ps) findlibfile { pop run } if pop
</tt></b></blockquote>
<p>
in files you want to use the improved algorithms. You may want to adapt
<b><tt>stcolor.ps</tt></b> file to your specific needs. The methods and
options for this are described here, but this description is restricted to
Ghostscript options, while their manipulation at the PostScript level is
documented in the material on <a href="Language.htm">the relationship of
Ghostscript and PostScript</a> and in <b><tt>stcolor.ps</tt></b>.
<h3><a name="STC_options"></a>Options</h3>
<p>
Now to explain the options (as written on my UNIX system). The order is
somehow related to their use during the printing process:
<dl>
<dt><b><tt>-dUnidirectional</tt></b>
<dd>Force unidirectional printing, recommended for transparencies
</dl>
<dl>
<dt><b><tt>-dMicroweave</tt></b>
<dd>Enable the printer's "microweave" feature; see
"<a href="#What_is_weaving">What is weaving?</a>" below.
</dl>
<dl>
<dt><b><tt>-dnoWeave</tt></b>
<dd>Disable any Weaving (overrides <b><tt>-dMicroweave</tt></b>)
</dl>
<dl>
<dt><b><tt>-dSoftweave</tt></b>
<dd>Enable the driver's internal weaving. Note that <b><tt>Softweave</tt></b> works <b>only</b> with the original Stylus Color and the PRO-Series.
</dl>
<dl>
<dt><b><tt>-sDithering=</tt></b><em>{name}</em>
<dd>Select another dithering algorithm (name) from among
<blockquote><table cellpadding=0 cellspacing=0>
<tr valign=top> <td><b><tt>gscmyk</tt></b>
<td>
<td>fast color output, CMYK process color model (default)
<tr valign=top> <td><b><tt>gsmono</tt></b>
<td>
<td>fast monochrome output
<tr valign=top> <td><b><tt>gsrgb</tt></b>
<td>
<td>fast color output, RGB process color model
<tr valign=top> <td><b><tt>fsmono</tt></b>
<td>
<td>Floyd-Steinberg, monochrome
<tr valign=top> <td><b><tt>fsrgb</tt></b>
<td>
<td>Floyd-Steinberg, RGB process color model (almost identical to the <b><tt>cdj550</tt></b>/<b><tt>bjc</tt></b> algorithm)
<tr valign=top> <td><b><tt>fsx4</tt></b>
<td>
<td>Floyd-Steinberg, CMYK process color model (shares code with <b><tt>fsmono</tt></b> and <b><tt>fsrgb</tt></b>, but is algorithmically really bad)
<tr valign=top> <td><b><tt>fscmyk</tt></b>
<td>
<td>Floyd-Steinberg, CMYK process color model and proper modifications for CMYK
<tr valign=top> <td><b><tt>hscmyk</tt></b>
<td>
<td>modified Floyd-Steinberg with CMYK model ("hs" stands for "hess" not for "high speed", but the major difference from <b><tt>fscmyk</tt></b> is speed)
<tr valign=top> <td><b><tt>fs2</tt></b>
<td>
<td>algorithm by Steven Singer (RGB) should be identical to <b><tt>escp2cfs2</tt></b>.
</table></blockquote>
</dl>
<dl>
<dt><b><tt>-dBitsPerPixel=</tt></b><em>{1...32}</em>
<dd>number of bits used for pixel storage; the larger the value, the better
the quality -- at least in theory. In <b><tt>fsrgb</tt></b> one can gain
some speed by restricting to 24 bits rather than the default 30.
</dl>
<dl>
<dt><b><tt>-dFlag0</tt></b>
<dd>causes some algorithms to select a uniform initialisation rather than a
set of random values. May yield a sharper image impression at the cost of
dithering artifacts. (Applies to <b><tt>hscmyk</tt></b> and all fs modes,
except for fs2, which always uses a constant initialization.)
</dl>
<dl>
<dt><b><tt>-dFlag1</tt></b> ... <b><tt>-dFlag4</tt></b>
<dd>Available for future algorithms.
</dl>
<dl>
<dt><b><tt>-dColorAdjustMatrix='{</tt></b><em>three, nine, or sixteen
floating-point values</em><b><tt>}'</tt></b>
<dd>This is a matrix to adjust the colors. Values should be between -1.0
and 1.0, and the number of values depends on the color model the selected
algorithm uses. In RGB and CMYK modes a matrix with 1.0 on the diagonal
produces no transformation. This feature is really required, but I could
not identify a similar feature at the language level, so I implemented it,
but I don't know reasonable values yet.
</dl>
<dl>
<dt><b><tt>-dCtransfer='{</tt></b><em>float float ...</em><b><tt>}'</tt></b> or
<dt><b><tt>-dMtransfer=</tt></b>..., <b><tt>-dY</tt></b>..., <b><tt>-dK</tt></b>... or
<dt><b><tt>-dRtransfer='{</tt></b><em>float float ...</em><b><tt>}'</tt></b> or
<dt><b><tt>-dG</tt></b>..., <b><tt>-dB</tt></b>... or
<dt><b><tt>-dKtransfer='{</tt></b><em>float float ...</em><b><tt>}'</tt></b>
<dd>Which you use depends on the algorithm, which may be either either
CMYK, RGB or monochrome. The values are arrays of floats in the range from
0 to 1.0, representing the visible color intensity for the device. One may
achieve similar effects with <b><tt>setcolortransfer</tt></b> at the
language level, but this takes more time and the underlying code for the
driver-specific parameters is still required. The size of the arrays is
arbitrary and the defaults are "<b><tt>{0.0 1.0}</tt></b>", which is a
linear characteristic. Most of the code in <b><tt>stcolor.ps</tt></b> are
better transfer arrays.
</dl>
<dl>
<dt><b><tt>-dKcoding='{</tt></b><em>float...</em><b><tt>}'</tt></b>
<dt><b><tt>-dC</tt></b>..., <b><tt>-dM</tt></b>... etc.
<dd>Arrays between 0.0 and 1.0, controlling the internal coding of the
color values. Clever use of these arrays may yield further enhancements,
but I have no experience yet. (To be discontinued with version 2.x.)
</dl>
<dl>
<dt><b><tt>-sModel=st800</tt></b>
<dd>Causes output to be suitable for the monochrome Stylus 800 (no weaving,
no color).
</dl>
<dl>
<dt><b><tt>-sOutputCode=</tt></b><em>{name}</em>
<dd>Can be either "<b><tt>plain</tt></b>", "<b><tt>runlength</tt></b>" or
"<b><tt>deltarow</tt></b>" and changes the ESC/P2 coding technique
used by the driver. The default is to use runlength encoding.
"<b><tt>plain</tt></b>" selects uncompressed encoding and generates
enormous amounts of data.
</dl>
<dl>
<dt><b><tt>-descp_Band=</tt></b><em>1/8/15/24</em>
<dd>Number of nozzles of scanlines used in printing, Useful only with
<b><tt>-dnoWeave</tt></b>. Larger Values yield smaller code, but this
doesn't increase the printing speed.
</dl>
<dl>
<dt><b><tt>-descp_Width=</tt></b><em>N</em>
<dd>Number of pixels Printed in each scan Line. (Useful only when tuning
margins; see below)
</dl>
<dl>
<dt><b><tt>-descp_Height=</tt></b><em>pixels</em>
<dd>Length of the entire page in pixels. (Parameter of
"<b><tt>ESC(C</tt></b>" in default initialization.)
</dl>
<dl>
<dt><b><tt>-descp_Top=</tt></b><em>scan lines</em>
<dd>Top margin in scan lines. (First parameter of "<b><tt>ESC(c</tt></b>"
in default initialization.)
</dl>
<dl>
<dt><b><tt>-descp_Bottom=</tt></b><em>scan lines</em>
<dd>Bottom margin in scan lines. (Second parameter of
"<b><tt>ESC(c</tt></b>" in default initialization.)
</dl>
<dl>
<dt><b><tt>-sescp_Init=</tt></b>"<em>string</em>"
<dd>Override for the initialization sequence. (Must set graphics mode 1
and units.)
</dl>
<dl>
<dt><b><tt>-sescp_Release=</tt></b>"<em>string</em>"
<dd>Overrides the release sequence, "<b><tt>ESC @ FF</tt></b>" by
default.
</dl>
<p>
ESC/P2 allows any resolutions to be valid in theory, but only
<b><tt>-r360x360</tt></b> (the default) and <b><tt>-r720x720</tt></b> (not
on STC-IIs ? and st800) are known to work with most printers.
<p>
<blockquote><table cellpadding=0 cellspacing=0>
<tr><th colspan=7 bgcolor="#CCCC00"><hr><font size="+1">Valid option combinations<br>Stylus I & Pro-Series only</font><hr>
<tr valign=bottom>
<th valign=bottom align=left>Resolution
<td>
<th valign=bottom align=left><b><tt>escp_Band</tt></b>
<td>
<th valign=bottom align=left>Weave usable
<td>
<th valign=bottom align=left><b><tt>escp_Band</tt></b> &<br>number of passes
<tr> <td colspan=7><hr>
<tr valign=top> <td>180x90
<td>
<td>15
<td>
<td><b><tt>noWeave</tt></b>
<td>
<td>
<tr valign=top> <td>180x180
<td>
<td>1 , 8, 24
<td>
<td><b><tt>noWeave</tt></b>, <b><tt>Microweave</tt></b>
<td>
<td>15/2 <b><tt>SoftWeave</tt></b>
<tr valign=top> <td>180x360
<td>
<td>
<td>
<td>
<td>
<td>15/4 <b><tt>SoftWeave</tt></b>
<tr valign=top> <td>180x720
<td>
<td>
<td>
<td>
<td>
<td>15/8 <b><tt>SoftWeave</tt></b>
<tr valign=top> <td>360x90
<td>
<td>15
<td>
<td><b><tt>noWeave</tt></b>
<td>
<td>
<tr valign=top> <td>360x180
<td>
<td>1, 8, 24
<td>
<td><b><tt>noWeave</tt></b>, <b><tt>Microweave</tt></b>
<td>
<td>15/2 <b><tt>SoftWeave</tt></b>
<tr valign=top> <td>360x360
<td>
<td>1, 8, 24
<td>
<td><b><tt>noWeave</tt></b>, <b><tt>Microweave</tt></b>
<td>
<td>15/4 <b><tt>SoftWeave</tt></b>
<tr valign=top> <td>360x720
<td>
<td>
<td>
<td>
<td>
<td>15/8 <b><tt>SoftWeave</tt></b>
<tr valign=top> <td>720x90
<td>
<td>15
<td>
<td><b><tt>noWeave</tt></b>
<td>
<td>
<tr valign=top> <td>720x180
<td>
<td>
<td>
<td>
<td>
<td>15/2 <b><tt>SoftWeave</tt></b>
<tr valign=top> <td>720x360
<td>
<td>
<td>
<td>
<td>
<td>15/4 <b><tt>SoftWeave</tt></b>
<tr valign=top> <td>720x720
<td>
<td>1
<td>
<td><b><tt>noWeave</tt></b>, <b><tt>Microweave</tt></b>
<td>
<td>15/8 <b><tt>SoftWeave</tt></b>
</table></blockquote>
<blockquote>
<b>Beware:</b> there are only few validity checks for parameters. A good
example is <b><tt>escp_Band</tt></b>: if you set this, the driver uses your
value even if the value is not supported by the printer. <b>You asked for
it and you got it!</b>
</blockquote>
<h3><a name="STC_FAQ"></a>Application note and FAQ</h3>
<p>
Quite a bunch of parameters. Hopefully you never need any of them, besides
feeding <b><tt>stcolor.ps</tt></b> to Ghostscript in front of your input.
<p>
After answering some questions over fifty times I prepared a FAQ. Here is
version 1.3 of the FAQ, as of <b><tt>stcolor</tt></b> version 1.20 (for
Ghostscript 3.50).
<h4><a name="STC_FAQ_A3"></a>Support for A3 paper</h4>
<p>
Yes, this driver supports the A3-size printer: merely set the required
pagesize and margins. A simple way to do this is to specify the
command-line switch "<b><tt>-sPAPERSIZE=a3</tt></b>" or include the
procedure call "<b><tt>a3</tt></b>" in the PostScript prolog section. To
optimize the printable area or set the proper margins, see the next
paragraph.
<h4><a name="STC_FAQ_margins"></a>Margins, PageSize</h4>
<p>
I refuse to add code to <b><tt>stcolor</tt></b> that tries to guess the
proper margins or page size, because I found that such guessing is usually
wrong and needs correction in either the source or the parameters. You can
modify <b><tt>stcolor.ps</tt></b> to do that, however. After the line
<blockquote><b><tt>
mark % prepare stack for "putdeviceprops"
</tt></b></blockquote>
<p>
insert these lines, which define page size and margins in points:
<blockquote>
<pre>/.HWMargins [9.0 39.96 12.6 9.0] % Left, bottom, right, top (1/72")
/PageSize [597.6 842.4] % Paper, including margins (1/72")
/Margins [ % neg. Offset to Left/Top in Pixels
4 index 0 get STCold /HWResolution get 0 get mul 72 div neg
5 index 3 get STCold /HWResolution get 1 get mul 72 div neg
]</pre></blockquote>
<p>
Feel free to change the values of <b><tt>.HWMargins</tt></b> and
<b><tt>PageSize</tt></b> to match your needs; the values given are the
defaults when the driver is compiled with "<b><tt>-DA4</tt></b>". This
option or its omission may cause trouble: the Stylus Color can print up to
exactly 8 inches (2880 pixels) at 360dpi. The remaining paper is the
margin, where the left margin varies only slightly with the paper size,
while the right margin is significantly increased for wider paper, such as
U.S. letter size.
<p>
<b>Note</b> that if you are using an ISO paper size with a version of
<b><tt>stcolor</tt></b> after 1.20 and compiled without
"<b><tt>-DA4</tt></b>", then the default margin is too large, and you need
to add the proper "<b><tt>.HWMargins</tt></b>" to the command line or to
<b><tt>stcolor.ps</tt></b>.
<h4><a name="STC_FAQ_II_IIS_1500"></a>Stylus Color II / IIs and 1500</h4>
<p>
First the good news: the driver can print on the Stylus Color II.
Now the bad news:
<ul>
<li>According to Epson support the driver "abuses" the color
capabilities. (See "Future Plans" for details.)
<li>You need some parameters on the command line (or in
<b><tt>stcolor.ps</tt></b>).
<li>I doubted that it would be usable with the Stylus Color IIs, but
it <b>is</b> usable and suffers from mixing problems!
</ul>
<p>
To make things work, you <b>MUST</b> disable the driver's internal
weaving (<b><tt>Softweave</tt></b>), in one of these two ways:
<blockquote>
<b><tt>gs -dMicroweave</tt></b> ...<br>
<b><tt>gs -dnoWeave -descp_Band=1</tt></b> ...
</blockquote>
<p>
Version 1.90, current as of Ghostscript 5.10, fixes this bug by new default
behaviour. I experienced significantly increased printing speed with the
second variant on the old Stylus Color, when printing mostly monochrome
data.
<h3><a name="STC_recommendations"></a>Recommendations</h3>
<p>
The next section is a contribution from Jason Patterson <jason@reflections.com.au>
who evaluated a previous version (1.17). Ghostscript was invoked as follows:
<blockquote><dl compact>
<dt><b><tt>gs</tt></b>
<dd><b><tt>-sDEVICE=stcolor -r720x720
-sDithering=</tt></b>... <b><tt>-sOutputFile=escp.out stcolor.ps
whatsoever.ps</tt></b>
</dl></blockquote>
<p>
where "..." is the name of the desired algorithm.
<b><tt>stcolor.ps</tt></b> was omitted for the gs-algorithms
(<b><tt>gsmono</tt></b>, <b><tt>gsrgb</tt></b> and <b><tt>gscmyk</tt></b>),
for which it is useless and would not allow the selection of
"<b><tt>gscmyk</tt></b>".
<h4><a name="STC_dither_experiment"></a>Color dithering experiments with
<b><tt>gdevstc</tt></b> 1.21</h4>
<p>
Here are data about the EPSON Stylus Color driver's different dithering
methods, based on a little experiment using four good quality scanned
images of quite varied nature, to begin with, a summary of the results of
the four experiments. <b>Sanity note:</b> the results here are from only
four images and a total of 24 printouts (eight on 720dpi paper, sixteen on
plain paper). Your results will almost certainly vary, and your standards
might not be the same as mine, so use these results only as a guide, not as
a formal evaluation.
<blockquote><table cellpadding=0 cellspacing=0>
<tr><th colspan=3 bgcolor="#CCCC00"><hr><font size="+1">Quality of output by method</font><hr>
<tr valign=bottom>
<th align=left>
<td>
<th align=left>
<tr> <td colspan=3><hr>
<tr> <td valign=top><b><tt>gsmono</tt></b>
<td>
<td>Pretty much what you'd expect from a mono ordered pattern.
Looks like what a lot of mono laser printers produce.
<tr> <td valign=top><b><tt>fsmono</tt></b>
<td>
<td>Excellent for monochrome.
<tr> <td valign=top><b><tt>gscmyk</tt></b>
<td>
<td>Not very good, but expected from an ordered pattern.
<tr> <td valign=top><b><tt>gsrgb</tt></b>
<td>
<td>A little better than <b><tt>gscmyk</tt></b>. More consistent
looking.
<tr> <td valign=top><b><tt>fs2</tt></b>
<td>
<td>Good, but not quite as good as <b><tt>fsrgb</tt></b>. Gets the
brightness wrong: too light at 720dpi, too dark at 360dpi.
<tr> <td valign=top><b><tt>fsrgb</tt></b>
<td>
<td>Very good, but a little too dark and has a slight blue tint.
<tr> <td valign=top><b><tt>hscmyk</tt></b>
<td>
<td>Excellent. Slightly better than <b><tt>fsrgb</tt></b> and
<b><tt>fs2</tt></b>. Better than <b><tt>fscmyk</tt></b> on
some images, almost the same on most.
<tr> <td valign=top><b><tt>fscmyk</tt></b>
<td>
<td>Best. Very, very slightly better than <b><tt>hscmyk</tt></b>.
On some images nearly as good as the EPSON demos done with
the MS Windows driver.
</table></blockquote>
<blockquote><table cellpadding=0 cellspacing=0>
<tr><th colspan=4 bgcolor="#CCCC00"><hr><font size="+1">Overall visual quality (1-10), best to worst</font><hr>
<tr valign=top> <th colspan=4 align=left>Monochrome
<tr> <td>
<td><b><tt>fsmono</tt></b>
<td>
<td><b><tt>******************</tt></b>
<tr> <td>
<td><b><tt>gsmono</tt></b>
<td>
<td><b><tt>**********</tt></b>
<tr> <td>
<td>
<td>
<td><b><tt>0 1 2 3 4 5 6 7 8 9 10</tt></b>
<tr> <td colspan=4><hr>
<tr valign=top> <th colspan=4 align=left>Colour
<tr> <td>
<td><b><tt>fscmyk</tt></b>
<td>
<td><b><tt>*******************</tt></b>
<tr> <td>
<td><b><tt>hscmyk</tt></b>
<td>
<td><b><tt>*******************</tt></b>
<tr> <td>
<td><b><tt>fsrgb</tt></b>
<td>
<td><b><tt>******************</tt></b>
<tr> <td>
<td><b><tt>fs2</tt></b>
<td>
<td><b><tt>*****************</tt></b>
<tr> <td>
<td><b><tt>gsrgb</tt></b>
<td>
<td><b><tt>**********</tt></b>
<tr> <td>
<td><b><tt>gscmyk</tt></b>
<td>
<td><b><tt>*********</tt></b>
<tr> <td>
<td>
<td>
<td><b><tt>0 1 2 3 4 5 6 7 8 9 10</tt></b>
</table></blockquote>
<h3><a name="STC_color_transform"></a>Color transformation</h3>
<p>
In the initial version of the driver distributed with Ghostscript 3.33, the
parameter "<b><tt>SpotSize</tt></b>" was the only way to manipulate the
colors at the driver level. According to the parameters enumerated above,
this has changed significantly with version 1.16 and above as a result an
ongoing discussion about dithering algorithms and "false color" on the
Epson Stylus Color. This initiated the transformation of the
<b><tt>stcolor</tt></b> driver into a framework for different dithering
algorithms, providing a generalized interface to the internal Ghostscript
color models and the other data structures related to Ghostscript drivers.
<p>
The main thing such a framework should be able to do is to deliver the
values the dithering algorithm needs; and since this directly influences
the optical image impression, this transformation should be adjustable
without the need for recompilation and relinking. In general the process
can be described as follows:
<blockquote><table cellpadding=0 cellspacing=0>
<tr valign=top> <td colspan=3><b><tt>ColorAdjustMatrix</tt></b>
<td align=center>Coding
<td colspan=3>
<td align=center>Transfer
<td colspan=3>
<tr valign=top> <td>|
<td align=center>Ghostscript color
<td>|
<td align=center>=>
<td>|
<td align=center>Ghostscript raster
<td>|
<td align=center>=>
<td>|
<td align=center>Dithering data
<td>|
<tr valign=top> <td>|
<td>
<td>|
<td>
<td>|
<td align=center>1/2/4/8/16/32-bit
<td>|
<td>
<td>|
<td>
<td>|
<tr valign=top> <td>|
<td align=center>1/3/4 16-bit values
<td>|
<td>
<td>|
<td align=center>1/3/4 values
<td>|
<td>
<td>|
<td align=center>(arbitrary type)
<td>|
</table></blockquote>
<p>
Due to the limitations on raster storage, information is lost in the first
transformation step, except for the 16-bit monochrome mode. So any color
adjustment should take place before this step and this is where the optional
<b><tt>ColorAdjustMatrix</tt></b> works.
<p>
The first transformation step, called "coding", is controlled by the
<b><tt>?coding</tt></b> arrays. The decoding process expands the range of
values expontentially to a larger range than that provided by the initial
Ghostscript color model, and is therefore a reasonable place to make
device- or algorithm-specific adjustments. This is where the
<b><tt>?transfer</tt></b> arrays are used. Array access might be not the
fastest method, but its generality is superior, so this step is always
based upon internally algorithm-specific array access. If 8 bits are stored
per color component and if the algorithm uses bytes too, the second
transformation is included within the first, which saves significant
computation time when printing the data.
<h3><a name="STC_CAM"></a><b><tt>ColorAdjustMatrix</tt></b></h3>
<p>
The driver supports different values for <b><tt>ProcessColorModel</tt></b>,
which raises the need for different color adjustments. Here
"<b><tt>CAM</tt></b>" stands for "<b><tt>ColorAdjustMatrix</tt></b>".
<dl>
<dt><b><tt>DeviceGray</tt></b> (three floats)
<dd><pre>if ((r == g) && (g == b))
K' = 1.0 - R;
else
K' = 1.0 - CAM[0] * R + CAM[1] * G + CAM[2] * B;</pre>
<p>
According to the <a href="Drivers.htm">documentation on drivers</a>, the
latter (the "else" clause) should never happen.
</dl>
<dl>
<dt><b><tt>DeviceRGB</tt></b> (nine floats)
<dd><pre>if((r == g) && (g == b))
R' = B' = G' = R;
else
R' = CAM[0]*R + CAM[1]*G + CAM[2]*B;
G' = CAM[3]*R + CAM[4]*G + CAM[5]*B;
B' = CAM[6]*R + CAM[7]*G + CAM[8]*B;</pre>
<p>
The printer always uses four inks, so a special treatment of black is
provided. Algorithms may take special action if R, G, and B are all
equal.
</dl>
<dl>
<dt><b><tt>DeviceCMYK</tt></b> (sixteen floats)
<dd>
<pre>if((c == m) && (m == y))
K' = max(C,K);
C' = M' = Y' = 0;
else
K = min(C,M,Y);
if((K > 0) && ColorAdjustMatrix_present) { => UCR
C -= K;
M -= K;
Y -= K;
}
C' = CAM[ 0]*C + CAM[ 1]*M + CAM[ 2]*Y + CAM[ 3]*K;
M' = CAM[ 4]*C + CAM[ 5]*M + CAM[ 6]*Y + CAM[ 7]*K;
Y' = CAM[ 8]*C + CAM[ 9]*M + CAM[10]*Y + CAM[11]*K;
K' = CAM[12]*C + CAM[13]*M + CAM[14]*Y + CAM[15]*K;</pre>
<p>
Again we have a special black treatment. "<b><tt>max(C,K)</tt></b>" was introduced
because of a slight misbehaviour of Ghostscript, which delivers
black under certain circumstances as (1,1,1,0). Normally, when
no special black separation and undercolor removal procedures
are defined at the PostScript level, either (C,M,Y,0) or (0,0,0,K)
values are mapped. This would make the extended <b><tt>ColorAdjustMatrix</tt></b>
quite tedious, and so during mapping, black separation is done for
(C,M,Y,0) requests; and if there is a <b><tt>ColorAdjustMatrix</tt></b>, undercolor
removal is used too. In other words the default matrix is:
<blockquote><table>
<tr> <td>1 <td>0 <td>0 <td>1
<tr> <td>0 <td>1 <td>0 <td>1
<tr> <td>0 <td>0 <td>1 <td>1
<tr> <td>0 <td>0 <td>0 <td>1
</table></blockquote>
<p>
and it is applied to CMYK values with separated and removed black. Raising
the CMY coefficients while lowering the K coefficients reduces black and
intensifies color. But be careful, because even small deviations from the
default cause drastic changes.
</dl>
<p>
If no <b><tt>ColorAdjustMatrix</tt></b> is set, the matrix computations are
skipped. Thus the transformation reduces to range inversion in monochrome
mode and black separation in CMYK mode.
<h3><a name="STC_RGBCMYK_coding"></a>RGB / CMYK coding and transfer, and <b><tt>BitsPerPixel</tt></b></h3>
<p>
These two (groups of) parameters are arrays of floating-point numbers in
the range 0.0 to 1.0. They control the truncation to the desired number of
bits stored in raster memory (<b><tt>BitsPerPixel</tt></b>) and the ink
density. The "truncation" may become a nonlinear function if any of the
<b><tt>?coding</tt></b> arrays is set. Assume the following Ghostscript
invocation:
<blockquote><pre>gs -sDEVICE=stcolor -sDithering=fscmyk -dBitsPerPixel=16 \
-dKcoding='{ 0.0 0.09 0.9 1.0 }' \
-dMcoding='{ 0.0 0.09 0.9 1.0 }' \
-dKtransfer='{ 0.0 0.09 0.9 1.0 }' \
-dYtransfer='{ 0.0 0.09 0.9 1.0 }'</pre>
</blockquote>
<p>
We may have either or both of <b><tt>?coding</tt></b> and
<b><tt>?transfer</tt></b>, giving four possible combinations. (These four
combinations appear in the given example.) The resulting mapping appears
in the following tables, where except for the internal Indices (4
components × 4 bits = 16 <b><tt>BitsPerPixel</tt></b>), all values
are normalized to the range 0 to 1. The actual range is 0 to 65535 for the
Ghostscript color and 0 to 16777215 for the ink values delivered to the
<b><tt>fscmyk</tt></b> algorithm. Sorry for the bunch of numbers
following, but you may try this example in conjunction with
<b><tt>stcinfo.ps</tt></b>, which should give you a graphical printout of
the following numbers when you issue a <b><tt>showpage</tt></b> command.
<blockquote><table cellpadding=0 cellspacing=0>
<tr> <td>
<td>
<th colspan=5>Cyan<hr>
<td>
<th colspan=5>Magenta<hr>
<tr valign=top> <th>CI/15
<td>
<th>gs_color_values
<td>
<th>CI
<td>
<th>Ink
<td>
<th>gs_color_values
<td>
<th>CI
<td>
<th>Ink
<tr> <td colspan=13><hr>
<tr valign=top> <td align=center>0.000
<td>
<td align=center>0.000 - 0.062
<td>
<td align=right>0
<td>
<td align=center>0.000
<td>
<td align=center>-0.123 - 0.123
<td>
<td align=right>0
<td>
<td align=center>0.000
<tr valign=top> <td align=center>0.067
<td>
<td align=center>0.063 - 0.125
<td>
<td align=right>1
<td>
<td align=center>0.067
<td>
<td align=center>0.123 - 0.299
<td>
<td align=right>1
<td>
<td align=center>0.247
<tr valign=top> <td align=center>0.133
<td>
<td align=center>0.125 - 0.187
<td>
<td align=right>2
<td>
<td align=center>0.133
<td>
<td align=center>0.299 - 0.365
<td>
<td align=right>2
<td>
<td align=center>0.351
<tr valign=top> <td align=center>0.200
<td>
<td align=center>0.188 - 0.250
<td>
<td align=right>3
<td>
<td align=center>0.200
<td>
<td align=center>0.365 - 0.392
<td>
<td align=right>3
<td>
<td align=center>0.379
<tr valign=top> <td align=center>0.267
<td>
<td align=center>0.250 - 0.312
<td>
<td align=right>4
<td>
<td align=center>0.267
<td>
<td align=center>0.392 - 0.420
<td>
<td align=right>4
<td>
<td align=center>0.406
<tr valign=top> <td align=center>0.333
<td>
<td align=center>0.313 - 0.375
<td>
<td align=right>5
<td>
<td align=center>0.333
<td>
<td align=center>0.420 - 0.447
<td>
<td align=right>5
<td>
<td align=center>0.433
<tr valign=top> <td align=center>0.400
<td>
<td align=center>0.375 - 0.437
<td>
<td align=right>6
<td>
<td align=center>0.400
<td>
<td align=center>0.447 - 0.475
<td>
<td align=right>6
<td>
<td align=center>0.461
<tr valign=top> <td align=center>0.467
<td>
<td align=center>0.438 - 0.500
<td>
<td align=right>7
<td>
<td align=center>0.467
<td>
<td align=center>0.475 - 0.502
<td>
<td align=right>7
<td>
<td align=center>0.488
<tr valign=top> <td align=center>0.533
<td>
<td align=center>0.500 - 0.562
<td>
<td align=right>8
<td>
<td align=center>0.533
<td>
<td align=center>0.502 - 0.529
<td>
<td align=right>8
<td>
<td align=center>0.516
<tr valign=top> <td align=center>0.600
<td>
<td align=center>0.563 - 0.625
<td>
<td align=right>9
<td>
<td align=center>0.600
<td>
<td align=center>0.529 - 0.557
<td>
<td align=right>9
<td>
<td align=center>0.543
<tr valign=top> <td align=center>0.667
<td>
<td align=center>0.625 - 0.687
<td>
<td align=right>10
<td>
<td align=center>0.667
<td>
<td align=center>0.557 - 0.584
<td>
<td align=right>10
<td>
<td align=center>0.571
<tr valign=top> <td align=center>0.733
<td>
<td align=center>0.688 - 0.750
<td>
<td align=right>11
<td>
<td align=center>0.733
<td>
<td align=center>0.584 - 0.612
<td>
<td align=right>11
<td>
<td align=center>0.598
<tr valign=top> <td align=center>0.800
<td>
<td align=center>0.750 - 0.812
<td>
<td align=right>12
<td>
<td align=center>0.800
<td>
<td align=center>0.612 - 0.639
<td>
<td align=right>12
<td>
<td align=center>0.626
<tr valign=top> <td align=center>0.867
<td>
<td align=center>0.813 - 0.875
<td>
<td align=right>13
<td>
<td align=center>0.867
<td>
<td align=center>0.639 - 0.715
<td>
<td align=right>13
<td>
<td align=center>0.653
<tr valign=top> <td align=center>0.933
<td>
<td align=center>0.875 - 0.937
<td>
<td align=right>14
<td>
<td align=center>0.933
<td>
<td align=center>0.715 - 0.889
<td>
<td align=right>14
<td>
<td align=center>0.778
<tr valign=top> <td align=center>1.000
<td>
<td align=center>0.938 - 1.000
<td>
<td align=right>15
<td>
<td align=center>1.000
<td>
<td align=center>0.889 - 1.111
<td>
<td align=right>15
<td>
<td align=center>1.000
</table></blockquote>
<p>
The difference between cyan and magenta is the presence of a coding array.
The coding process must map a range of color values to each of the sixteen
component indices. If no coding array is given, this is accomplished
by dividing by 4096, equivalent to a right shift by 12 bits. The
final ink density resides in the given interval and moves from the left to
the right side from 0 to 15. For magenta there is a coding array
and the ink value matches the center of the intervals. But the distribution
of the mapped intervals follows the given coding array and is nonlinear in
the linear color space of Ghostscript.
<p>
Now let us take a look at the case with transfer arrays:
<blockquote><table cellpadding=0 cellspacing=0>
<tr> <td>
<td>
<th colspan=5>Yellow<hr>
<td>
<th colspan=5>Black<hr>
<tr valign=top> <th>CI/15
<td>
<th>gs_color_values
<td>
<th>CI
<td>
<th>Ink
<td>
<th>gs_color_values
<td>
<th>CI
<td>
<th>Ink
<tr> <td colspan=13><hr>
<tr valign=top> <td align=center>0.000
<td>
<td align=center>0.000 - 0.062
<td>
<td align=right>0
<td>
<td align=center>0.000
<td>
<td align=center>-0.123 - 0.123
<td>
<td align=right>0
<td>
<td align=center>0.000
<tr valign=top> <td align=center>0.067
<td>
<td align=center>0.063 - 0.125
<td>
<td align=right>1
<td>
<td align=center>0.018
<td>
<td align=center>0.123 - 0.299
<td>
<td align=right>1
<td>
<td align=center>0.067
<tr valign=top> <td align=center>0.133
<td>
<td align=center>0.125 - 0.187
<td>
<td align=right>2
<td>
<td align=center>0.036
<td>
<td align=center>0.299 - 0.365
<td>
<td align=right>2
<td>
<td align=center>0.133
<tr valign=top> <td align=center>0.200
<td>
<td align=center>0.188 - 0.250
<td>
<td align=right>3
<td>
<td align=center>0.054
<td>
<td align=center>0.365 - 0.392
<td>
<td align=right>3
<td>
<td align=center>0.200
<tr valign=top> <td align=center>0.267
<td>
<td align=center>0.250 - 0.312
<td>
<td align=right>4
<td>
<td align=center>0.072
<td>
<td align=center>0.392 - 0.420
<td>
<td align=right>4
<td>
<td align=center>0.267
<tr valign=top> <td align=center>0.333
<td>
<td align=center>0.313 - 0.375
<td>
<td align=right>5
<td>
<td align=center>0.090
<td>
<td align=center>0.420 - 0.447
<td>
<td align=right>5
<td>
<td align=center>0.333
<tr valign=top> <td align=center>0.400
<td>
<td align=center>0.375 - 0.437
<td>
<td align=right>6
<td>
<td align=center>0.252
<td>
<td align=center>0.447 - 0.475
<td>
<td align=right>6
<td>
<td align=center>0.400
<tr valign=top> <td align=center>0.467
<td>
<td align=center>0.438 - 0.500
<td>
<td align=right>7
<td>
<td align=center>0.414
<td>
<td align=center>0.475 - 0.502
<td>
<td align=right>7
<td>
<td align=center>0.467
<tr valign=top> <td align=center>0.533
<td>
<td align=center>0.500 - 0.562
<td>
<td align=right>8
<td>
<td align=center>0.576
<td>
<td align=center>0.502 - 0.529
<td>
<td align=right>8
<td>
<td align=center>0.533
<tr valign=top> <td align=center>0.600
<td>
<td align=center>0.563 - 0.625
<td>
<td align=right>9
<td>
<td align=center>0.738
<td>
<td align=center>0.529 - 0.557
<td>
<td align=right>9
<td>
<td align=center>0.600
<tr valign=top> <td align=center>0.667
<td>
<td align=center>0.625 - 0.687
<td>
<td align=right>10
<td>
<td align=center>0.900
<td>
<td align=center>0.557 - 0.584
<td>
<td align=right>10
<td>
<td align=center>0.667
<tr valign=top> <td align=center>0.733
<td>
<td align=center>0.688 - 0.750
<td>
<td align=right>11
<td>
<td align=center>0.920
<td>
<td align=center>0.584 - 0.612
<td>
<td align=right>11
<td>
<td align=center>0.733
<tr valign=top> <td align=center>0.800
<td>
<td align=center>0.750 - 0.812
<td>
<td align=right>12
<td>
<td align=center>0.940
<td>
<td align=center>0.612 - 0.639
<td>
<td align=right>12
<td>
<td align=center>0.800
<tr valign=top> <td align=center>0.867
<td>
<td align=center>0.813 - 0.875
<td>
<td align=right>13
<td>
<td align=center>0.960
<td>
<td align=center>0.639 - 0.715
<td>
<td align=right>13
<td>
<td align=center>0.867
<tr valign=top> <td align=center>0.933
<td>
<td align=center>0.875 - 0.937
<td>
<td align=right>14
<td>
<td align=center>0.980
<td>
<td align=center>0.715 - 0.889
<td>
<td align=right>14
<td>
<td align=center>0.933
<tr valign=top> <td align=center>1.000
<td>
<td align=center>0.938 - 1.000
<td>
<td align=right>15
<td>
<td align=center>1.000
<td>
<td align=center>0.889 - 1.111
<td>
<td align=right>15
<td>
<td align=center>1.000
</table></blockquote>
<p>
Yellow uses a transfer array. There is no linear correspondence between
the color and the ink values: this correspondence is defined through the
given array. In other words, the transfer arrays define a nonlinear ink
characteristic, which is exactly the same functionality that PostScript's
"(color)transfer" function provides.
<p>
While for yellow the intervals match the intervals used with cyan, for
black the intervals match the magenta intervals. But watch the
correspondence between the CI/15 values and the ink density for black: this
is a linear distribution in the ink domain.
<p>
Not a bad idea, I think. Consider the <b><tt>fs2</tt></b> algorithm: it
uses values in the range 0 to 255. If any transfer array were alone, some
of the 256 possible values would never be used and others would be used for
adjacent intervals several times. Establishing an identical coding array
solves this problem, so the full potential of the algorithm is used.
<p>
Another useful feature of the coding arrays is that they are internally
normalized to the range 0-1. In 720x720dpi mode the transfer arrays in
<b><tt>stcolor.ps</tt></b> limit the dot density to about 50%, so these
arrays end at 0.5 (and begin at 0.5 for RGB). Because of automatic
normalization, these arrays can also be used as coding arrays. But of
course in the <b><tt>fs2</tt></b> case mentioned above, values from 0 to
127 will never be delivered to the algorithm, while values 128-255 are
delivered for adjacent intervals.
<p>
To clarify the intended use of the three parameters (parameter groups), keep this in mind:
<blockquote><ul>
<li><b><tt>ColorAdjustMatrix</tt></b> is never used when transferring gray
values. This restricts it to what the name says: adjustment of colors,
that is, correction for miscolored ink. Do not use it for saturation or
brightness control.
<li><b><tt>?transfer</tt></b> arrays control the values delivered to the
driver, which in turn controls the ink quantity. Use these arrays to
control saturation and brightness. In general these arrays are identical
for all inks. If they differ they provide a simpler scheme for color
correction, which is not necessarily faster than the
<b><tt>ColorAdjustMatrix</tt></b>.
<li><b><tt>?coding</tt></b> arrays control the color value intervals mapped
to the internal color indices.
</ul></blockquote>
<h3><a name="What_is_weaving"></a>What is weaving?</h3>
<p>
The Epson Stylus Color has a head assembly that contains two physically
identifiable heads, one for black and one for cyan, magenta, and yellow
(CMY). This makes four "logical" heads, one for each color component.
Each of these four heads has several jets at some vertical (Y) distance
from one another, so several horizontal lines can be printed of a given
color during one pass of the heads. From experience I think there are
fifteen jets per color, spaced at 1/90in.
<p>
So the question arises of how to print at a Y resolution of 360dpi with
90dpi jets. Simply by division one gets 360dpi/90dpi = 4, which tells us
that 4 passes of the head assembly are needed to achieve a Y resolution of
360dpi.
<p>
Weaving is the method of how the fifteen jets are used to print adjacent
horizontal rows separated here by 1/360 inch:
<blockquote><table cellpadding=0 cellspacing=0>
<tr><th colspan=17 bgcolor="#CCCC00"><hr><font size="+1">Print-head jets used with and without weaving</font><hr>
<tr> <td>
<td>
<th valign=bottom colspan=7>Weaving<hr>
<td>
<th valign=bottom colspan=7>noWeave<hr>
<tr valign=top> <td>
<th>Pass
<th>1
<td>
<th>2
<td>
<th>3
<td>
<th>4
<td>
<th>1
<td>
<th>2
<td>
<th>3
<td>
<th>4
<tr> <th>Row
<tr valign=top> <td align=center>0
<td>
<td align=center>jet 0
<td>
<td align=center>--
<td>
<td align=center>--
<td>
<td align=center>--
<td>
<td align=center>jet 0
<td>
<td align=center>--
<td>
<td align=center>--
<td>
<td align=center>--
<tr valign=top> <td align=center>1
<td>
<td align=center>--
<td>
<td align=center>jet 1
<td>
<td align=center>--
<td>
<td align=center>--
<td>
<td align=center>--
<td>
<td align=center>jet 0
<td>
<td align=center>--
<td>
<td align=center>--
<tr valign=top> <td align=center>2
<td>
<td align=center>--
<td>
<td align=center>--
<td>
<td align=center>jet 2
<td>
<td align=center>--
<td>
<td align=center>--
<td>
<td align=center>--
<td>
<td align=center>jet 0
<td>
<td align=center>--
<tr valign=top> <td align=center>3
<td>
<td align=center>--
<td>
<td align=center>--
<td>
<td align=center>--
<td>
<td align=center>jet 3
<td>
<td align=center>--
<td>
<td align=center>--
<td>
<td align=center>--
<td>
<td align=center>jet 0
<tr valign=top> <td align=center>4
<td>
<td align=center>jet 1
<td>
<td align=center>--
<td>
<td align=center>--
<td>
<td align=center>--
<td>
<td align=center>jet 1
<td>
<td align=center>--
<td>
<td align=center>--
<td>
<td align=center>--
<tr valign=top> <td align=center>5
<td>
<td align=center>--
<td>
<td align=center>jet 2
<td>
<td align=center>--
<td>
<td align=center>--
<td>
<td align=center>--
<td>
<td align=center>jet 1
<td>
<td align=center>--
<td>
<td align=center>--
<tr valign=top> <td align=center>6
<td>
<td align=center>--
<td>
<td align=center>--
<td>
<td align=center>jet 3
<td>
<td align=center>--
<td>
<td align=center>--
<td>
<td align=center>--
<td>
<td align=center>jet 1
<td>
<td align=center>--
<tr valign=top> <th>...
</table></blockquote>
<p>
Now let's assume that the dot diameter is different for each individual
jet, but the average among the jets matches the desired resolution. With
weaving, adjacent rows are printed by different jets, thus some averaging
takes place. Without weaving, adjacent rows are printed by the same jet
and this makes the dot diameter deviations visible as 1/90in stripes on
the paper.
<h3><a name="STC_print_modes"></a>Print mode parameters</h3>
<p>
The parameters "<b><tt>Unidirectional</tt></b>",
"<b><tt>Microweave</tt></b>", "<b><tt>noWeave</tt></b>",
"<b><tt>OutputCode</tt></b>", "<b><tt>Model</tt></b>" and the given
resolution control the data generated for the printer.
<h4><a name="STC_unidirectional"></a><b><tt>Unidirectional</tt></b></h4>
<p>
Simply toggles the unidirectional mode of the printer. Setting
"<b><tt>Unidirectional</tt></b>" definitely slows printing speed, but may
improve the quality. I use this for printing transparencies, where fast
head movement could smear the ink.
<h4><a name="STC_noweave"></a><b><tt>Microweave</tt></b>,
<b><tt>noWeave</tt></b> and <b><tt>OutputCode=deltarow</tt></b></h4>
<p>
The first are two booleans, which implies that four combinations are
possible. Actually only three exist (if you don't count for
<b><tt>deltarow</tt></b>): <b><tt>Softweave</tt></b>,
<b><tt>Microweave</tt></b>, and <b><tt>noWeave</tt></b>. The first and
second are functionally identical, the difference being whether the driver
or the printer does the job.
<p>
In the default <b><tt>Softweave</tt></b> mode the driver sends the data
properly arranged to the printer, while in <b><tt>Microweave</tt></b> mode,
it is the printer that arranges the data. But in general the host processor
is much faster than the printer's processor, and thus it is faster for the
host do the job. In addition to that, for 720dpi eight passes are
required, and the amount of buffer space needed to buffer the data for the
passes is far beyond the printer's memory. <b><tt>Softweave</tt></b>
requires an odd value of "<b><tt>escp_Band</tt></b>"; the Stylus Color
provides fifteen for that.
<p>
"<b><tt>OutputCode</tt></b>" controls the encoding used. In the basic
modes, the choice consists of "plain" and "runlength". The computation of
runlength-encoded data does not take much time, less than the data tranfer
to the printer; thus this is the recommended mode, and of course the
default. With the Stylus Color, Epson introduced some new encoding
principles, namely "tiff" and "deltarow". While the first was omitted from
this driver for lack of apparent advantages, "<b><tt>deltarow</tt></b>" is
available as an option. "<b><tt>Softweave</tt></b>" cannot be used with
this encoding, so if <b><tt>OutputCode=deltarow</tt></b> is set,
<b><tt>Microweave</tt></b> becomes the default. Maybe that the size of the
ESC/P2 code becomes smaller, but I have never observed faster printing
speed. Things tend to become slower with <b><tt>deltarow</tt></b> compared
to <b><tt>Softweave</tt></b>.
<h4><a name="STC_model"></a><b><tt>Model</tt></b></h4>
<p>
Some ESC/P2 printers such as the Stylus 800 do not offer
<b><tt>Microweave</tt></b> or the commands required to do
<b><tt>Softweave</tt></b>. Setting <b><tt>Model</tt></b> just changes the
defaults and omits some parts of the initialization sequence which are not
compatible with the given printer model. Currently only
"<b><tt>st800</tt></b>" is supported besides the default
<b><tt>stcolor</tt></b>.
<h3><a name="STC_Pitfalls"></a>Bugs and pitfalls</h3>
<ul>
<li>The given <b><tt>?coding</tt></b> and <b><tt>?transfer</tt></b> arrays
should be strictly monotonic.
<li>It is impossible to change <b><tt>WHITE</tt></b>: that's your paper.
Thus RGB transfer should end at 1.0 and CMYK transfer should start at 0.0.
<li>Usually 8 bits per component yields fastest operation.
<li>The <b><tt>ColorAdjustMatrix</tt></b> is not used in the reverse
transformation used when Ghostscript does the dithering
(<b><tt>gs</tt></b>* modes). Expect funny results.
<li>If <b><tt>BitsPerPixel</tt></b> is less than 6, the entire coding and
transfer process does not work. This is always true for the
<b><tt>gs</tt></b>* modes and becomes true for the other modes if
<b><tt>BitsPerPixel</tt></b> is forced to low values.
<li>720×720dpi printing should never select the <b><tt>gs</tt></b>*
modes and should always use <b><tt>stcolor.ps</tt></b>. (I prefer
360×720.)
</ul>
<h3><a name="STC_Tests"></a>Tests</h3>
<p>
This section gives an overview of performance in terms of processing and
printing times, from tests run after version 1.13. Printing was done
offline (simply copying a processed file to the printer) to measure real
printing speed without regard to speed of processing on the host, since at
high resolutions, processing time is the same order of magnitude and thus
may become the limiting factor.
<h4><a name="STC_OutputCodes"></a>The various OutputCodes</h4>
<p>
I ran several files though Ghostscript and recorded the size of the
resulting print code, the processing time, and the printing time, at least
for some of the files, always using these options:
<blockquote><b><tt>
gs -sDEVICE=stcolor -sPAPERSIZE=a4 stcolor.ps - < file.ps
</tt></b></blockquote>
<p>
(Actually "<b><tt>-sPAPERSIZE=a4</tt></b>" is in my
<b><tt>gs_init.ps</tt></b> since I'm a germ.)
<p>"<b><tt>deltarow</tt></b>" is the new encoding principle
("<b><tt>ESC . 3 10 10 1</tt></b>") with
<b><tt>Microweave</tt></b> on. It is activated with
"<b><tt>-sOutputCode=deltarow</tt></b>".
<p>"<b><tt>Softweave</tt></b>" actually means that nothing else was used:
it is the default, and implies that odd v=40/h=10/m=15 mode
("<b><tt>ESC . 1 40 10 15</tt></b>").
<p>"<b><tt>Microweave</tt></b>" means "<b><tt>-dMicroweave</tt></b>",
equivalent to "<b><tt>ESC . 1 10 10 1</tt></b>",
with full skip optimization and microweave activated.
<p>
Finally I wanted to see the plain Kathy Ireland, and used
"<b><tt>-sOutputCode=plain</tt></b>", which just replaces runlength
encoding (RLE) by no encoding, thus using
"<b><tt>ESC . 0 40 10 15</tt></b>". [So sorry
<b><tt>;-)</tt></b> Kathy was still dressed in blue in front of the blue
sea on a blue air cushion -- nice to see but hard to dither.]
<p>
So here are the results.
<blockquote><table cellpadding=0 cellspacing=0>
<tr><th colspan=9 bgcolor="#CCCC00"><hr><font size="+1">File sizes and printing speeds with various weaving methods</font><hr>
<tr valign=bottom>
<td>
<td>
<th><b><tt>golfer.ps</tt></b>
<td>
<th><b><tt>colorcir.ps</tt></b>
<td>
<th><b><tt>drawing.ps</tt></b>
<td>
<th><b><tt>brief.ps</tt></b>
<tr> <td colspan=9><hr>
<tr valign=top> <td><b><tt>deltarow</tt></b>
<td>
<td>572751/48.180u
<td>
<td>643374/41.690u
<td>
<td>90142/46.180u/1:50
<td>
<td>178563/49.350u/2:22
<tr valign=top> <td><b><tt>Softweave</tt></b>
<td>
<td>559593/46.810u
<td>
<td>669966/44.960u
<td>
<td>296168/48.160u/1:30
<td>
<td>269808/43.320u/1:55
<tr valign=top> <td><b><tt>Microweave</tt></b>
<td>
<td>590999/56.060u
<td>
<td>754276/42.890u
<td>
<td>338885/47.060u/1:50
<td>
<td>282314/44.690u/2:22
</table></blockquote>
<blockquote><table cellpadding=0 cellspacing=0>
<tr><th colspan=3 bgcolor="#CCCC00"><hr><font size="+1">Kathy Ireland</font><hr>
<tr valign=bottom>
<td>
<td>
<th><b><tt>kathy.ps</tt></b>
<tr> <td colspan=3><hr>
<tr valign=top> <td><b><tt>deltarow</tt></b>
<td>
<td>3975334/111.940u/5:35
<tr valign=top> <td><b><tt>Softweave</tt></b>
<td>
<td>3897112/101.940u/3:10
<tr valign=top> <td><b><tt>Microweave</tt></b>
<td>
<td>4062829/100.990u/3:15
<tr valign=top> <td><b><tt>plain/soft</tt></b>
<td>
<td>5072255/104.390u/3:05
</table></blockquote>
<p>
It may be that I've not chosen the optimal <b><tt>deltarow</tt></b> code,
but even if it saves at lot of bytes, printing-speed is not increased.
<p>
At least the printer prefers plain Kathy. In other words, sending 1
Megabyte or 20% more data has no impact on printing speed.
<b><tt>drawing.ps</tt></b> is an exception to this rule: plain prints
slower than RLE.
<p>
"Unclever" coding -- especially with <b><tt>deltarow</tt></b> -- can
significantly slow down printing. But even if very significant advantages
in the size of the code are achieved, "<b><tt>deltarow</tt></b>" is not
competitive. <b><tt>colorcir.ps</tt></b> shows savings with
<b><tt>deltarow</tt></b>, but printing is a mess.
<h4><a name="STC_printing_time"></a>Printing time related to other options</h4>
<p>
Full page halftone images printed, unless otherwise noted.
<blockquote><table cellpadding=0 cellspacing=0>
<tr><th colspan=11 bgcolor="#CCCC00"><hr><font size="+1">Printing time related to other options</font><hr>
<tr valign=top> <th>dpi
<td>
<th colspan=3>Print mode
<td>
<th>Size KB
<td>
<th>Time
<td>
<th align=left>Comments
<tr> <td colspan=11><hr>
<tr valign=top> <td>180x180
<td>
<td>mono
<td>
<td align=right>-/uni
<td>
<td align=right>358
<td>
<td align=right>1:15
<td>
<td>
<tr valign=top> <td>
<td>
<td align=right>
<td>
<td align=right>-/bi
<td>
<td align=right>358
<td>
<td align=right>0:45
<td>
<td>
<tr valign=top> <td>
<td>
<td align=right>
<td>
<td align=right>micro/bi
<td>
<td align=right>205
<td>
<td align=right>0:45
<td>
<td>Not weaving
<tr valign=top> <td>
<td>
<td align=right>
<td>
<td align=right>soft/bi
<td>
<td align=right>179
<td>
<td align=right>1:25
<td>
<td>
<tr valign=top> <td>
<td>
<td>color
<td>
<td align=right>-/bi
<td>
<td align=right>641
<td>
<td align=right>2:45
<td>
<td>
<tr valign=top> <td>
<td>
<td align=right>
<td>
<td align=right>soft/bi
<td>
<td align=right>556
<td>
<td align=right>1:32
<td>
<td>
<tr valign=top> <td>360x360
<td>
<td>mono
<td>
<td align=right>-/uni
<td>
<td align=right>269
<td>
<td align=right>0:50
<td>
<td>Monochrome text
<tr valign=top> <td>
<td>
<td align=right>
<td>
<td align=right>-/bi
<td>
<td align=right>269
<td>
<td align=right>0:35
<td>
<td>Monochrome text
<tr valign=top> <td>
<td>
<td align=right>
<td>
<td align=right>micro/bi
<td>
<td align=right>269
<td>
<td align=right>2:25
<td>
<td>Monochrome text
<tr valign=top> <td>
<td>
<td align=right>
<td>
<td align=right>soft/uni
<td>
<td align=right>250
<td>
<td align=right>3:15
<td>
<td>Monochrome text
<tr valign=top> <td>
<td>
<td align=right>
<td>
<td align=right>soft/bi
<td>
<td align=right>250
<td>
<td align=right>1:55
<td>
<td>Monochrome text
<tr valign=top> <td>
<td>
<td>color
<td>
<td align=right>-/bi
<td>
<td align=right>346
<td>
<td align=right>1:00
<td>
<td>Sparse-color page, visible displacements
<tr valign=top> <td>
<td>
<td align=right>
<td>
<td align=right>micro/bi
<td>
<td align=right>346
<td>
<td align=right>1:50
<td>
<td>Sparse-color page, looks buggy -- printer?
<tr valign=top> <td>
<td>
<td align=right>
<td>
<td align=right>soft/bi
<td>
<td align=right>294
<td>
<td align=right>1:30
<td>
<td>Sparse-color page, O.K.
<tr valign=top> <td>
<td>
<td align=right>
<td>
<td align=right>-/bi
<td>
<td align=right>2218
<td>
<td align=right>2:45
<td>
<td>Visible stripes
<tr valign=top> <td>
<td>
<td align=right>
<td>
<td align=right>micro/bi
<td>
<td align=right>5171
<td>
<td align=right>3:17
<td>
<td>
<tr valign=top> <td>
<td>
<td align=right>
<td>
<td align=right>soft/bi
<td>
<td align=right>3675
<td>
<td align=right>3:05
<td>
<td>
<tr valign=top> <td>360x720
<td>
<td>mono
<td>
<td align=right>soft/bi
<td>
<td align=right>2761
<td>
<td align=right>5:40
<td>
<td>
<tr valign=top> <td>
<td>
<td>color
<td>
<td align=right>soft/bi
<td>
<td align=right>7789
<td>
<td align=right>6:15
<td>
<td>Just a small difference!
<tr valign=top> <td>720x360
<td>
<td>color
<td>
<td align=right>soft/bi
<td>
<td align=right>7182
<td>
<td align=right>5:40
<td>
<td>
<tr valign=top> <td>720x720
<td>
<td>color
<td>
<td align=right>micro/bi
<td>
<td align=right>14748
<td>
<td align=right>30:26
<td>
<td>Actually beyond printer's capabilities
<tr valign=top> <td>
<td>
<td align=right>
<td>
<td align=right>soft/bi
<td>
<td align=right>14407
<td>
<td align=right>11:08
<td>
<td>
</table></blockquote>
<h3><a name="STC_acks"></a>Acknowledgments</h3>
<p>
This driver was copied from <b><tt>gdevcdj.c</tt></b> (Ghostscript 3.12),
which was contributed by George Cameron, Koert Zeilstra, and Eckhard
Rueggeberg. Some of the ESC/P2 code was drawn from Richard Brown's
<b><tt>gdevescp.c</tt></b>. The POSIX interrupt code (compilation option
<b><tt>-DSTC_SIGNAL</tt></b>) is from Frederic Loyer. Several improvements
are based on discussions with Brian Converse, Bill Davidson, Gero Guenther,
Jason Patterson, ? Rueschstroer, and Steven Singer.
<p>
While I wish to thank everyone mentioned above, they are by no means
responsible for bugs in the stcolor driver -- just for the features.
<address>
Gunther Hess<br>
Richard Wagner Strasse 112<br>
D-47057 Duisburg<br>
Germany<br>
+49 203 376273 telephone (MET evening hours)<br>
<<a href="mailto:ghess@elmos.de">ghess@elmos.de</a>>
</address>
<hr>
<h2><a name="Uniprint"></a>uniprint, a flexible unified printer driver</h2>
<p>
<b><tt>uniprint</tt></b> is a unified parametric driver by Gunther Hess
<<a href="mailto:ghess@elmos.de">ghess@elmos.de</a>> for several
kinds of printers and devices, including
<blockquote>
<ul>
<li>any Epson Stylus Color, Stylus, or Stylus Pro
<li>HP PCL/RTL
<li>Canon BubbleJet Color 610
<li>NEC P2X
<li>Sun raster file format
</ul></blockquote>
<p>
This driver is intended to <em>become</em> a unified printer driver. If you
consider it ugly, please send me your suggestions for improvements. The
driver will be updated with them. Thus the full explanation of the driver's
name is:
<blockquote>
Ugly- -> Updated- -> Unified Printer Driver
</blockquote>
<p>
But you probably want to know something about the functionality.
At the time of this writing uniprint drives:
<ul>
<li>NEC Pinwriter P2X (24-pin monochrome impact printer, ESC/P style)
<li>Several Epson Stylus Color models (ESC/P2 style)
<li>HP-DeskJet 550c (basic HP-RTL)
<li>Canon BJC 610
</ul>
<p>
It can be configured for various other printers without recompilation
and offers uncompressed (ugly) Sun rasterfiles as another format, but
this format is intended for testing purposes rather than real use.
The usage of this driver is quite simple. The typical command line looks
like this:
<blockquote>
<b><tt>gs @</tt></b>{MODEL}<b><tt>.upp -sOutputFile=</tt></b>{printable file}<b><tt> MyFile.ps -c quit</tt></b>
</blockquote>
<p>
For example, from my Linux box:
<blockquote><b><tt>
gs @stc.upp -sOutputFile=/dev/lp1 tiger.ps -c quit
</tt></b></blockquote>
<blockquote><table cellpadding=0 cellspacing=0>
<tr><th colspan=6 bgcolor="#CCCC00"><hr><font size="+1">Unified Printer Parameter files distributed with Ghostscript</font><hr>
<tr> <th align=left colspan=6>Canon BJC 610 (color, rendered)
<tr valign=top> <td>
<td><b><tt>bjc610a0.upp</tt></b>
<td>
<td>360×360dpi
<td>
<td>plain paper, high speed
<tr valign=top> <td>
<td><b><tt>bjc610a1.upp</tt></b>
<td>
<td>360×360dpi
<td>
<td>plain paper
<tr valign=top> <td>
<td><b><tt>bjc610a2.upp</tt></b>
<td>
<td>360×360dpi
<td>
<td>coated paper
<tr valign=top> <td>
<td><b><tt>bjc610a3.upp</tt></b>
<td>
<td>360×360dpi
<td>
<td>transparency film
<tr valign=top> <td>
<td><b><tt>bjc610a4.upp</tt></b>
<td>
<td>360×360dpi
<td>
<td>back print film
<tr valign=top> <td>
<td><b><tt>bjc610a5.upp</tt></b>
<td>
<td>360×360dpi
<td>
<td>fabric sheet
<tr valign=top> <td>
<td><b><tt>bjc610a6.upp</tt></b>
<td>
<td>360×360dpi
<td>
<td>glossy paper
<tr valign=top> <td>
<td><b><tt>bjc610a7.upp</tt></b>
<td>
<td>360×360dpi
<td>
<td>high gloss film
<tr valign=top> <td>
<td><b><tt>bjc610a8.upp</tt></b>
<td>
<td>360×360dpi
<td>
<td>high resolution paper
<tr> <td>
<tr valign=top> <td>
<td><b><tt>bjc610b1.upp</tt></b>
<td>
<td>720×720dpi
<td>
<td>plain paper
<tr valign=top> <td>
<td><b><tt>bjc610b2.upp</tt></b>
<td>
<td>720×720dpi
<td>
<td>coated paper
<tr valign=top> <td>
<td><b><tt>bjc610b3.upp</tt></b>
<td>
<td>720×720dpi
<td>
<td>transparency film
<tr valign=top> <td>
<td><b><tt>bjc610b4.upp</tt></b>
<td>
<td>720×720dpi
<td>
<td>back print film
<tr valign=top> <td>
<td><b><tt>bjc610b6.upp</tt></b>
<td>
<td>720×720dpi
<td>
<td>glossy paper
<tr valign=top> <td>
<td><b><tt>bjc610b7.upp</tt></b>
<td>
<td>720×720dpi
<td>
<td>high-gloss paper
<tr valign=top> <td>
<td><b><tt>bjc610b8.upp</tt></b>
<td>
<td>720×720dpi
<td>
<td>high resolution paper
<tr> <td>
<tr> <th align=left colspan=6>HP Ink-Printers
<tr valign=top> <td>
<td><b><tt>cdj550.upp</tt></b>
<td>
<td>300×300dpi
<td>
<td>32-bit CMYK
<tr valign=top> <td>
<td><b><tt>cdj690.upp</tt></b>
<td>
<td>300×300dpi
<td>
<td>Normal mode
<tr valign=top> <td>
<td><b><tt>cdj690ec.upp</tt></b>
<td>
<td>300×300dpi
<td>
<td>Economy mode
<tr valign=top> <td>
<td><b><tt>dnj750c.upp</tt></b>
<td>
<td>300×300dpi
<td>
<td>Color -- also good for 450C
<tr valign=top> <td>
<td><b><tt>dnj750m.upp</tt></b>
<td>
<td>600×600dpi
<td>
<td>Monochrome
<tr> <td>
<tr> <th align=left colspan=6>NEC P2X
<tr valign=top> <td>
<td><b><tt>necp2x.upp</tt></b>
<td>
<td>360×360dpi
<td>
<td>8-bit (Floyd-Steinberg)
<tr> <td>
<tr> <th align=left colspan=6>Any Epson Stylus Color
<tr valign=top> <td>
<td><b><tt>stcany.upp</tt></b>
<td>
<td>360×360dpi
<td>
<td>4-bit, PostScript halftoning
<tr valign=top> <td>
<td><b><tt>stcany_h.upp</tt></b>
<td>
<td>720×720dpi
<td>
<td>4-bit, PostScript halftoning
<tr> <td>
<tr> <th align=left colspan=6>Original Epson Stylus and Stylus Pro Color
<tr valign=top> <td>
<td><b><tt>stc.upp</tt></b>
<td>
<td>360×360dpi
<td>
<td>32-bit CMYK, 15-pin
<tr valign=top> <td>
<td><b><tt>stc_l.upp</tt></b>
<td>
<td>360×360dpi
<td>
<td>4-bit, PostScript halftoning, weaved noWeave
<tr valign=top> <td>
<td><b><tt>stc_h.upp</tt></b>
<td>
<td>720×720dpi
<td>
<td>32-bit CMYK, 15-pin Weave
<tr> <td>
<tr> <th align=left colspan=6>Epson Stylus Color II
<tr valign=top> <td>
<td><b><tt>stc2.upp</tt></b>
<td>
<td>360×360dpi
<td>
<td>32-bit CMYK, 20-pin, Epson Stylus Color II(s)
<tr valign=top> <td>
<td><b><tt>stc2_h.upp</tt></b>
<td>
<td>720×720dpi
<td>
<td>32-bit CMYK, 20-pin, Epson Stylus Color II
<tr valign=top> <td>
<td><b><tt>stc2s_h.upp</tt></b>
<td>
<td>720×720dpi
<td>
<td>32-bit CMYK, 20-pin, Epson Stylus Color IIs
<tr> <td>
<tr> <th align=left colspan=6>Epson Stylus Color 200
<tr valign=top> <td>
<td><b><tt>stc200.upp</tt></b>
<td>
<td>360×720dpi
<td>
<td>Plain Paper
<tr> <td>
<tr> <th align=left colspan=6>Epson Stylus Color 300
<tr valign=top> <td>
<td><b><tt>stc300.upp</tt></b>
<td>
<td>360×360dpi
<td>
<td>32-bit CMYK, plain paper
<tr valign=top> <td>
<td><b><tt>stc300bl.upp</tt></b>
<td>
<td>180×180dpi
<td>
<td>black only, plain paper
<tr valign=top> <td>
<td><b><tt>stc300bm.upp</tt></b>
<td>
<td>360×360dpi
<td>
<td>black only, plain paper
<tr> <td>
<tr> <th align=left colspan=6>Epson Stylus Color 500 (good transfer curves for plain paper)
<tr valign=top> <td>
<td><b><tt>stc500p.upp</tt></b>
<td>
<td>360×360dpi
<td>
<td>32-bit CMYK, noWeave, plain paper
<tr valign=top> <td>
<td><b><tt>stc500ph.upp</tt></b>
<td>
<td>720×720dpi
<td>
<td>32-bit CMYK, noWeave, plain paper
<tr> <td>
<tr> <th align=left colspan=6>Epson Stylus Color 600, 32/90-inch weaving
<tr valign=top> <td>
<td><b><tt>stc600pl.upp</tt></b>
<td>
<td>360×360dpi
<td>
<td>32-bit CMYK, 32-pin, plain paper
<tr valign=top> <td>
<td><b><tt>stc600p.upp</tt></b>
<td>
<td>720×720dpi
<td>
<td>32-bit CMYK, 32-pin, plain paper
<tr valign=top> <td>
<td><b><tt>stc600ih.upp</tt></b>
<td>
<td>1440×720dpi
<td>
<td>32-bit CMYK, 30-pin, inkjet paper
<tr> <td>
<tr> <th align=left colspan=6>Epson Stylus Color 640
<tr valign=top> <td>
<td><b><tt>stc640p.upp</tt></b>
<td>
<td>720×720dpi
<td>
<td>plain paper?
<tr valign=top> <td>
<td><b><tt>st640p.upp</tt></b>
<td>
<td>720×720dpi
<td>
<td>CMYK, plain paper
<tr valign=top> <td>
<td><b><tt>st640pg.upp</tt></b>
<td>
<td>720×720dpi
<td>
<td>grayscale, plain paper
<tr valign=top> <td>
<td><b><tt>st640pl.upp</tt></b>
<td>
<td>360×360dpi
<td>
<td>CMYK, plain paper
<tr valign=top> <td>
<td><b><tt>st640plg.upp</tt></b>
<td>
<td>360×360dpi
<td>
<td>grayscale, plain paper
<tr valign=top> <td>
<td><b><tt>st640ih.upp</tt></b>
<td>
<td>1440×720dpi
<td>
<td>CMYK, inkjet paper
<tr valign=top> <td>
<td><b><tt>st640ihg.upp</tt></b>
<td>
<td>1440×720dpi
<td>
<td>grayscale, inkjet paper
<tr> <td>
<tr> <th align=left colspan=6>Epson Stylus Color 800, 64/180-inch weaving
<tr valign=top> <td>
<td><b><tt>stc800pl.upp</tt></b>
<td>
<td>360×360dpi
<td>
<td>32-bit CMYK, 64-pin, plain paper
<tr valign=top> <td>
<td><b><tt>stc800p.upp</tt></b>
<td>
<td>720×720dpi
<td>
<td>32-bit CMYK, 64-pin, plain paper
<tr valign=top> <td>
<td><b><tt>stc800ih.upp</tt></b>
<td>
<td>1440×720dpi
<td>
<td>32-bit CMYK, 62-pin, inkjet paper
<tr valign=top> <td>
<td><b><tt>stc1520.upp</tt></b>
<td>
<td>1440×720dpi
<td>
<td>32-bit CMYK, 62-pin, inkjet paper
<tr> <td>
<tr> <th align=left colspan=6>Sun raster file
<tr valign=top> <td>
<td><b><tt>ras1.upp</tt></b>
<td>
<td>1-bit
<td>
<td>monochrome (Ghostscript)
<tr valign=top> <td>
<td><b><tt>ras3.upp</tt></b>
<td>
<td>3-bit
<td>
<td>RGB (Ghostscript)
<tr valign=top> <td>
<td><b><tt>ras4.upp</tt></b>
<td>
<td>4-bit
<td>
<td>CMYK (Ghostscript)
<tr valign=top> <td>
<td><b><tt>ras8m.upp</tt></b>
<td>
<td>8-bit
<td>
<td>grayscale (Floyd-Steinberg)
<tr valign=top> <td>
<td><b><tt>ras24.upp</tt></b>
<td>
<td>24-bit
<td>
<td>RGB (Floyd-Steinberg)
<tr valign=top> <td>
<td><b><tt>ras32.upp</tt></b>
<td>
<td>32-bit
<td>
<td>CMYK (CMYK-Floyd-Steinberg)
</table></blockquote>
<p>
Thanks to Danilo Beuche, Guido Classen, Mark Goldberg and Hans-Heinrich
Viehmann for providing the files for the stc200, hp690, stc500 and the
stc640. Thanks to Michael Lossin <losse@germanymail.com> for the
newer st640 parameter sets.
<p>
Please note the following:
<blockquote><ul>
<li>Changing the resolution with Ghostscript's
<a href="Use.htm#Resolution_switch"><b><tt>-r</tt></b> switch</a> is
usually not possible.
<li>For Epson Stylus Color models not listed above, the two
<b><tt>stc500</tt></b> variants are likely to work in addition to
<b><tt>stcany</tt></b>, but their gamma correction might be wrong.
</ul></blockquote>
<h3><a name="Uni_state"></a>The state of this driver</h3>
<p>
The coding of <b><tt>uniprint</tt></b> was triggered by the requirements of
the various Stylus Color models and some personal needs for HP and NEC
drivers. Thus the Epson models are well represented among the distributed
parameter files. When this driver entered the beta test phase, three other
drivers appreared on the scene that could be at least partially integrated
into <b><tt>uniprint</tt></b>: <b><tt>cdj850</tt></b> by Uli Wortmann
(available at <a href="http://www.erdw.ethz.ch/~bonk/hp850/hp850.html">http://www.erdw.ethz.ch/~bonk/hp850/hp850.html</a>),
<b><tt>hpdj</tt></b> by Martin Lottermoser, and <b><tt>bjc610</tt></b> by
Helmut Riegler.
<p>
Uli addresses features of the more recent DeskJet models that will not be
available in <b><tt>uniprint</tt></b> soon. Martin taught me a lesson on
HP-PCL3 headers that will be available in <b><tt>uniprint</tt></b>
soon. Helmut in turn followed an almost similar idea, but targetted
primarily for printing on Canon printers from the pbmplus library. Starting
with version 1.68 of uniprint, BJC support is available. Work on the
<b><tt>hpdj</tt></b> integration will start after the update of my website.
<h3><a name="Uni_background"></a>Notes on <b><tt>uniprint</tt></b>'s background</h3>
<p>
<b><tt>uniprint</tt></b> is actually an update of <b><tt>stcolor</tt></b>,
but much more versatile than its predecessor; <b><tt>stcolor</tt></b>, in
its turn, started as a clone of the color DeskJet family of drivers
(<b><tt>cdj</tt></b>*). Finally, <b><tt>cdj</tt></b>* can be considered an
addition of features to the simpler monochrome drivers of Ghostscript. This
addition of features is useful to get an idea of the functionality of
<b><tt>uniprint</tt></b>:
<blockquote>
<dl>
<dt>Monochrome to advanced color (<b><tt>cdj</tt></b>*):
<dd>This adds color mapping and rendering functions to the driver.
Error diffusion is especially important for the quality of printing.
</dl>
<dl>
<dt>HP color to Epson Color (<b><tt>stcolor</tt></b>)
<dd>The Epson Stylus Color offered two features simultaneously: it could
produce 720×720dpi output and it could soak the paper. In other
words, it required more color management features inside the driver. This
is still the major conceptual difference in the data generation for HP and
Epson printers.
</dl>
<dl>
<dt>Weaving techniques (<b><tt>stcolor</tt></b>)
<dd>Besides the internal color management, the Stylus Color did not provide
enough buffer space to operate the printer fast at 720×720dpi. The
use of weaving could yield triple the print speed. Weaving, also called
interleaving, is present in some monochrome drivers too. The new thing in
<b><tt>stcolor</tt></b> was the combination with error diffusion.
Unfortunately the weaving was somehow hard-coded, as the problems with the
newer members of the Stylus Color family of printers demonstrated.
</dl>
<dl>
<dt>Generalized output format and weaving (<b><tt>uniprint</tt></b>)
<dd>The features mentioned above yield about 90% of
<b><tt>stcolor</tt></b>'s source code; only 10% is related to the
formatting of the output. The idea to make the output format switchable
came up soon after completing <b><tt>stcolor</tt></b>, but its final design
was triggered by the (personal) necessity to drive a NEC P2X and a
Designjet 750c.
</dl></blockquote>
<p>
Thus <b><tt>uniprint</tt></b> accumulates almost any features that can be
found among the other printer drivers, which clearly has some disadvantage
in processing speed -- true in particular of version 1.75, since it was
targetted for functionality, and several speed-gaining features were
(knowingly) omitted.
<p>
To summarize and to introduce the terms used in the description of the
parameters, the features of <b><tt>uniprint</tt></b> that can be
parameterized are:
<blockquote><ul>
<li>color mapping,
<li>color rendering (error diffusion or Floyd-Steinberg),
<li>output format, including
<li>weaving.
</ul></blockquote>
<h3><a name="Uni_make_pfile"></a>Godzilla's guide to the creation of Unified Printer Parameter (<b><tt>.upp</tt></b>) files</h3>
<p>
Here is one of the distributed parameter files (<b><tt>stc_l.upp</tt></b>)
with some added comments. Also see the section that describes
<a href="#Uni_all_parameters">all <b><tt>uniprint</tt></b>'s parameters in
brief</a>.
<pre>
-supModel="Epson Stylus Color I (and PRO Series), 360x360DpI, noWeave"
-sDEVICE=uniprint -- Select the driver
-dNOPAUSE -- Useful with printers
-dSAFER -- Provides some security
-dupColorModel=/DeviceCMYK -- Selects the color mapping
-dupRendering=/ErrorDiffusion -- Selects the color rendering
-dupOutputFormat=/EscP2 -- Selects the output format
-r360x360 -- Adjusts the resolution
-dupMargins="{ 9.0 39.96 9.0 9.0}" -- Establishes (L/B/R/T margins in points)
-dupComponentBits="{1 1 1 1}" -- Map: bits per component (default: 8)
-dupWeaveYPasses=4 -- Weave: Y-passes (default: 1)
-dupOutputPins=15 -- Format/weave: scans per Command
-dupBeginPageCommand="< -- Goes to the printer
1b40 1b40 -- ESC '@' ESC '@' -> dual reset
1b2847 0100 01 -- ESC '(' 'G' 1 0 1 -> graphics
1b2869 0100 00 -- ESC '(' 'i' 1 0 1 -> no HW weave
1b2855 0100 0A -- ESC '(' 'U' 1 0 10 -> 360dpi
1b5500 -- ESC 'U' 0 -> bidir print
1b2843 0200 0000 -- ESC '(' 'C' 2 0 xx -> page length
1b2863 0400 0000 0000 -- ESC '(' 'c' 4 0 xxxx -> margins
>" -- as it is, unless:
-dupAdjustPageLengthCommand -- Adjust page length in BOP requested
-dupAdjustTopMarginCommand -- Adjust top margin in BOP
-dupAdjustBottomMarginCommand -- Adjust bottom margin in BOP
-dupEndPageCommand="(\033@\014)" -- Last (but one) data to the printer
-dupAbortCommand="(\033@\15\12\12\12\12 Printout-Aborted\15\014)"
</pre>
<p>
That's short, and if one removes <b><tt>upWeaveYPasses</tt></b> and
<b><tt>upOutputPins</tt></b> it becomes shorter, almost
<b><tt>stcany.upp</tt></b>. This miniature size is because I am most
familiar with ESC/P2, and was able to add defaults for the omitted
parameters. Now a few notes about the parameters used in this example:
<ul>
<li><b><tt>upModel</tt></b> is a string serving as a comment (and nothing else).
<li><a href="Use.htm#Output_device"><b><tt>DEVICE</tt></b></a>,
<a href="Use.htm#NoPause"><b><tt>NOPAUSE</tt></b></a>, <a
href="Use.htm#Safer"><b><tt>SAFER</tt></b></a> are well-known Ghostscript
parameters described in the <a href="Use.htm">usage documentation</a>.
<li><b><tt>upColorModel</tt></b> is one of major <b><tt>uniprint</tt></b>
parameters: it selects the color mapping and in turn the PostScript color
model. It supports the devices <b><tt>/DeviceGray</tt></b>, <b><tt>/DeviceRGBW</tt></b>, <b><tt>/DeviceRGB</tt></b>, <b><tt>/DeviceCMYK</tt></b>, and <b><tt>/DeviceCMYKgenerate</tt></b>.
<li><b><tt>upRendering</tt></b> selects the (color) rendering, supporting
the values <b><tt>/ErrorDiffusion</tt></b> and <b><tt>/FSCMYK32</tt></b>.
<b><tt>/ErrorDiffusion</tt></b> is similar to <b><tt>fsmono</tt></b>,
<b><tt>fsrgb</tt></b> and <b><tt>fsx4</tt></b> of <b><tt>stcolor</tt></b>,
while <b><tt>/FSCMYK32</tt></b> is (almost) identical to
<b><tt>fscmyk</tt></b> and <b><tt>hscmyk</tt></b>, but is restricted to
32-bit data and should be used in conjunction with
<b><tt>/DeviceCMYKgenerate</tt></b>.
<li><b><tt>upOutputFormat</tt></b> selects the output method, supporting the values
<b><tt>/SunRaster</tt></b>, <b><tt>/Epson</tt></b>, <b><tt>/EscP2</tt></b>, <b><tt>/EscP2XY</tt></b>, and<b><tt>/Pcl</tt></b>.
<blockquote><table cellpadding=0 cellspacing=0>
<tr valign=top> <td><b><tt>/SunRaster</tt></b>
<td>
<td>creates Sun raster files and requires no other parameters
<tr valign=top> <td><b><tt>/Epson</tt></b>
<td>
<td>is used for the elderly ESC/P format (used by many printers)
<tr valign=top> <td><b><tt>/EscP2</tt></b>
<td>
<td>is used by more recent Epson printers (no X weaving supported)
<tr valign=top> <td><b><tt>/EscP2XY</tt></b>
<td>
<td>supports X-Weaving, used with 1440dpi printers and in <b><tt>stc2s_h</tt></b>
<tr valign=top> <td><b><tt>/Pcl</tt></b>
<td>
<td>HP PCL/RTL-style output formatter without weaving
</table></blockquote>
<li><b><tt>-r360x360</tt></b> is Ghostscript's standard
<a href="Use.htm#Resolution_switch">resolution switch</a>.
<li><b><tt>upMargins="{ 9.0 39.96 9.0 9.0}"</tt></b>
has function similar to the Ghostscript parameter
<b><tt>.HWMargins</tt></b>: it sets the left, bottom, right, and top
margins in points. <b><tt>uniprint</tt></b> provides this parameter to
enable automatic left-right exchange if <b><tt>upYFlip</tt></b> is active.
<li><b><tt>upComponentBits</tt></b> is an array of integers that selects
the bits stored in raster memory, by default 8 bits per component. In this
example, 1 bit is selected for each component, thus turning down the
Floyd-Steinberg algorithm (but still carrying out the time-consuming
computation). The related parameter "<b><tt>upComponentShift</tt></b>"
controls positioning the components within raster memory. Each of the
numbers given corresponds to a component which depends on the selected
"<b><tt>upColorModel</tt></b>":
<blockquote><table cellpadding=0 cellspacing=0>
<tr valign=top> <td align=center>
<td>
<td align=center><b><tt>/DeviceGray</tt></b>
<td>
<td align=center><b><tt>/DeviceRGBW</tt></b>
<td>
<td align=center><b><tt>/DeviceRGB</tt></b>
<td>
<td align=center><b><tt>/DeviceCMYK</tt></b>
<td>
<td align=center><b><tt>/DeviceCMYKgenerate</tt></b>
<tr> <td colspan=11><hr>
<tr valign=top> <td align=center>0
<td>
<td align=center>White
<td>
<td align=center>White
<td>
<td align=center>Red
<td>
<td align=center>Black
<td>
<td align=center>Black
<tr valign=top> <td align=center>1
<td>
<td align=center>--
<td>
<td align=center>Red
<td>
<td align=center>Green
<td>
<td align=center>Cyan
<td>
<td align=center>Cyan
<tr valign=top> <td align=center>2
<td>
<td align=center>--
<td>
<td align=center>Green
<td>
<td align=center>Blue
<td>
<td align=center>Magenta
<td>
<td align=center>Magenta
<tr valign=top> <td align=center>3
<td>
<td align=center>--
<td>
<td align=center>Blue
<td>
<td align=center>--
<td>
<td align=center>Yellow
<td>
<td align=center>Yellow
</table>
<p>
This order may not be suitable for some printers, so another parameter
"<b><tt>upOutputComponentOrder</tt></b>", also an array of integers,
selects the output order using the numbers on the left.
</blockquote>
<p>
One group of very important parameters not used in the example above
deserves to be mentioned here: the transfer arrays, named
"<b><tt>up</tt><em>{color}</em><tt>Transfer</tt></b>", where
<b><em>{color}</em></b> is one of the names in the table above. These are
arrays of floats in the range 0.0 - 1.0 representing the color transfer
functions. They are used during mapping and rendering. In the simplest
case, these arrays ensure an equidistant distribution of the stored values
within the device space (which means a nonlinear mapping from Ghostscript's
point of view). If the given array does not cover the entire range from 0
to 1, which applies for the Stylus Color family at high resolution for some
media, only the relevant part gets mapped to raster memory (meaning that
is's fully utilized) and the rendering takes care of the "overhang" (in
this case the post-diffusion of 1-bit components makes sense).
<p>
Finally an important note on the transfer arrays: for monochrome devices
the stored component is <b><tt>White</tt></b>, which is the way PostScript
defines these devices, but most printers require <b><tt>Black</tt></b>.
Thus one has to provide a falling "<b><tt>upWhiteTransfer</tt></b>" for
such printers.
<li><b><tt>upWeaveYPasses</tt></b> is an integer that gives the number of
print head passes required to achieve the requested Ydpi. This makes sense
only if
<li><b><tt>upOutputPins</tt></b> is set to something greater than 1. Thus
multiple pins or nozzles are transferred with a single command, and of
course such a command must be supported by the device.
</ul>
<p>
If no other weave parameters are given, <b><tt>uniprint</tt></b> computes
several defaults which together do no weaving. The <b><tt>/Epson</tt></b>
and <b><tt>/EscP2XY</tt></b> formats take care of
"<b><tt>upWeaveXPasses</tt></b>" too.
<ul>
<li><b><tt>upBeginPageCommand</tt></b> represents the data transferred to
the printer whenever a new page begins. Before that,
"<b><tt>upBeginJobCommand</tt></b>" is written to the device only once per
output file. (Intended for the HP PJL sequences).
<li><b><tt>upAdjustBottomMarginCommand</tt></b>,
<b><tt>upAdjustMediaSize</tt></b>,
<b><tt>upAdjustPageLengthCommand</tt></b>,
<b><tt>upAdjustPageWidthCommand</tt></b>,
<b><tt>upAdjustResolutionCommand</tt></b>, and
<b><tt>upAdjustTopMarginCommand</tt></b>
<p>
Normally <b><tt>uniprint</tt></b> does not change the
"<b><tt>upBeginPageCommand</tt></b>", nor does it provide a default.
However, if the above boolean values are set, the corresponding values are
changed (provided that the code of the formatters supports this change and
the commands to be adjusted are included in the BOP string).
<li><b><tt>upEndPageCommand</tt></b> is the fixed termination sequence for
each page, and of course there is an "<b><tt>upEndJobCommand</tt></b>" too.
<li><b><tt>upAbortCommand</tt></b> is written if <b><tt>uniprint</tt></b>'s
interrupt detection is enabled and a signal is caught. It replaces
"<b><tt>upEndPageCommand</tt></b>" and "<b><tt>upEndJobCommand</tt></b>",
thus allowing the indication of an aborted job. (Ghostscript gets an error
return from <b><tt>uniprint</tt></b> in this case, and abandons further
processing.)
</ul>
<p>
For the ESC/P(2) formats all commands represent binary data, while for
the PCL/RTL formatter some of them are formats for <b><tt>fprintf</tt></b>. These strings
<b><em>must</em></b> explicitly have a trailing "\0'.
<p>
I should write more, but the only recommendation is to
take a look at the various parameter files. Here are a few more hints.
<ul>
<li>If the Driver rejects a configuration, nothing happens until
<b><tt>showpage</tt></b>; then an error is raised and a message with
"CALL-REJECTED upd_print_page..." is printed on stderr.
<li><b><tt>uniprint</tt></b> has lots of messages that can be activated by
setting bits in the preprocessor macro <b><tt>UPD_MESSAGES</tt></b>. I
usually use the compile-time option <b><tt>-DUPD_MESSAGES=0x17</tt></b> for
configuration development. (For the semantics, check the
<b><tt>UPD_M_</tt></b> macros in the source.)
<li>A program "<b><tt>uninfo.ps</tt></b>" distributed with Ghostscript
displays interactively in alphabetical order the contents of the current
pagedevice dictionary. This includes any parameters generated or changed by
<b><tt>uniprint</tt></b>.
</ul>
<h3><a name="Uni_all_parameters"></a>All parameters in brief</h3>
<p>
This table gives a brief explanation of every parameter known to
<b><tt>uniprint</tt></b>, listing them in alphabetical order. "[ ]"
denotes that a parameter is an array, and "(RO)" that it is read-only.
<blockquote><table cellpadding=0 cellspacing=0>
<tr><th colspan=5 bgcolor="#CCCC00"><hr><font size="+1">All <b><tt>uniprint</tt></b> parameters</font><hr>
<tr valign=bottom>
<th align=left>Parameter
<td>
<th align=left>Type
<td>
<th align=left>Use
<tr> <td colspan=5><hr>
<tr valign=top> <td><b><tt>upAbortCommand</tt></b>
<td>
<td>String
<td>
<td>End of page and file on interrupt
<tr valign=top> <td><b><tt>upAdjustBottomMarginCommand</tt></b>
<td>
<td>Bool
<td>
<td>Manipulate bottom margin in <b><tt>upBeginPageCommand</tt></b>
<tr valign=top> <td><b><tt>upAdjustMediaSizeCommand</tt></b>
<td>
<td>Bool
<td>
<td>Manipulate <b><tt>Mediasize</tt></b> [intended]
<tr valign=top> <td><b><tt>upAdjustPageLengthCommand</tt></b>
<td>
<td>Bool
<td>
<td>Manipulate page length in <b><tt>upBeginPageCommand</tt></b>
<tr valign=top> <td><b><tt>upAdjustPageWidthCommand</tt></b>
<td>
<td>Bool
<td>
<td>Manipulate page width in <b><tt>upBeginPageCommand</tt></b>
<tr valign=top> <td><b><tt>upAdjustResolutionCommand</tt></b>
<td>
<td>Bool
<td>
<td>Manipulate resolution
<tr valign=top> <td><b><tt>upAdjustTopMarginCommand</tt></b>
<td>
<td>Bool
<td>
<td>Manipulate top margin in <b><tt>upBeginPageCommand</tt></b>
<tr valign=top> <td><b><tt>upBeginJobCommand</tt></b>
<td>
<td>String
<td>
<td>Begin each output file
<tr valign=top> <td><b><tt>upBeginPageCommand</tt></b>
<td>
<td>String
<td>
<td>Begin each page
<tr valign=top> <td><b><tt>upBlackTransfer</tt></b>
<td>
<td>Float[ ]
<td>
<td>Black transfer (CMYK only!)
<tr valign=top> <td><b><tt>upBlueTransfer</tt></b>
<td>
<td>Float[ ]
<td>
<td>Blue transfer
<tr valign=top> <td><b><tt>upColorInfo</tt></b>
<td>
<td>Int[ ]
<td>
<td>struct <b><tt>gx_device_color_info</tt></b>
<tr valign=top> <td><b><tt>upColorModel</tt></b>
<td>
<td>Name
<td>
<td>Select color mapping
<tr valign=top> <td><b><tt>upColorModelInitialized</tt></b>
<td>
<td>Bool (RO)
<td>
<td>Color mapping OK
<tr valign=top> <td><b><tt>upComponentBits</tt></b>
<td>
<td>Int[ ]
<td>
<td>Bits stored per component
<tr valign=top> <td><b><tt>upComponentShift</tt></b>
<td>
<td>Int[ ]
<td>
<td>Positioning within <b><tt>gx_color_index</tt></b>
<tr valign=top> <td><b><tt>upCyanTransfer</tt></b>
<td>
<td>Float[ ]
<td>
<td>Cyan transfer
<tr valign=top> <td><b><tt>upEndJobCommand</tt></b>
<td>
<td>String
<td>
<td>End each file unless <b><tt>upAbortCommand</tt></b>
<tr valign=top> <td><b><tt>upEndPageCommand</tt></b>
<td>
<td>String
<td>
<td>End each page unless <b><tt>upAbortCommand</tt></b>
<tr valign=top> <td><b><tt>upErrorDetected</tt></b>
<td>
<td>Bool (RO)
<td>
<td>Severe (VM) error, not fully operational
<tr valign=top> <td><b><tt>upFSFixedDirection</tt></b>
<td>
<td>Bool
<td>
<td>Inhbits direction toggling in rendering
<tr valign=top> <td><b><tt>upFSProcessWhiteSpace</tt></b>
<td>
<td>Bool
<td>
<td>Causes white-space rendering
<tr valign=top> <td><b><tt>upFSReverseDirection</tt></b>
<td>
<td>Bool
<td>
<td>Run rendering in reverse (if fixed)
<tr valign=top> <td><b><tt>upFSZeroInit</tt></b>
<td>
<td>Bool
<td>
<td>Non-random rendering initialization
<tr valign=top> <td><b><tt>upFormatXabsolute</tt></b>
<td>
<td>Bool
<td>
<td>Write absolute X coordinates
<tr valign=top> <td><b><tt>upFormatYabsolute</tt></b>
<td>
<td>Bool
<td>
<td>Write absolute Y coordinates
<tr valign=top> <td><b><tt>upGreenTransfer</tt></b>
<td>
<td>Float[ ]
<td>
<td>Green transfer
<tr valign=top> <td><b><tt>upMagentaTransfer</tt></b>
<td>
<td>Float[ ]
<td>
<td>Magenta transfer
<tr valign=top> <td><b><tt>upMargins</tt></b>
<td>
<td>Float[ ]
<td>
<td>L/B/R/T margins in points
<tr valign=top> <td><b><tt>upModel</tt></b>
<td>
<td>String
<td>
<td>Comment string, holds some info
<tr valign=top> <td><b><tt>upOutputAborted</tt></b>
<td>
<td>Bool (RO)
<td>
<td>Caught an interrupt
<tr valign=top> <td><b><tt>upOutputBuffers</tt></b>
<td>
<td>Int
<td>
<td>Number of rendering buffers (2^<small><sup><b>N</b></sup></small>)
<tr valign=top> <td><b><tt>upOutputComponentOrder</tt></b>
<td>
<td>Int[ ]
<td>
<td>Order of components when printing
<tr valign=top> <td><b><tt>upOutputComponents</tt></b>
<td>
<td>Int
<td>
<td>Number of written components, not fully operational
<tr valign=top> <td><b><tt>upOutputFormat</tt></b>
<td>
<td>Name
<td>
<td>Select output format
<tr valign=top> <td><b><tt>upOutputFormatInitialized</tt></b>
<td>
<td>Bool (RO)
<td>
<td>Format data OK
<tr valign=top> <td><b><tt>upOutputHeight</tt></b>
<td>
<td>Int
<td>
<td>Output height in pixels
<tr valign=top> <td><b><tt>upOutputPins</tt></b>
<td>
<td>Int
<td>
<td>Number of pins / nozzles per command
<tr valign=top> <td><b><tt>upOutputWidth</tt></b>
<td>
<td>Int
<td>
<td>Output width in pixels
<tr valign=top> <td><b><tt>upOutputXOffset</tt></b>
<td>
<td>Int
<td>
<td>Offset in pixels, if <b><tt>upFormatXabsolute</tt></b>
<tr valign=top> <td><b><tt>upOutputXStep</tt></b>
<td>
<td>Int
<td>
<td>Divisor or multiplier for X coords
<tr valign=top> <td><b><tt>upOutputYOffset</tt></b>
<td>
<td>Int
<td>
<td>Offset in pixels, if <b><tt>upFormatYabsolute</tt></b>
<tr valign=top> <td><b><tt>upOutputYStep</tt></b>
<td>
<td>Int
<td>
<td>Divisor or multiplier for Y coords
<tr valign=top> <td><b><tt>upRasterBufferInitialized</tt></b>
<td>
<td>Bool (RO)
<td>
<td>GS buffer OK
<tr valign=top> <td><b><tt>upRedTransfer</tt></b>
<td>
<td>Float[ ]
<td>
<td>Red transfer
<tr valign=top> <td><b><tt>upRendering</tt></b>
<td>
<td>Name
<td>
<td>Select rendering algorithm
<tr valign=top> <td><b><tt>upRenderingInitialized</tt></b>
<td>
<td>Bool (RO)
<td>
<td>Rendering parameters OK
<tr valign=top> <td><b><tt>upSelectComponentCommands</tt></b>
<td>
<td>String[ ]
<td>
<td>Establish color (output order!)
<tr valign=top> <td><b><tt>upSetLineFeedCommand</tt></b>
<td>
<td>String
<td>
<td>Adjust linefeed (Epson only)
<tr valign=top> <td><b><tt>upVersion</tt></b>
<td>
<td>String (RO)
<td>
<td>Source code version
<tr valign=top> <td><b><tt>upWeaveFinalPins</tt></b>
<td>
<td>Int[ ]
<td>
<td>Number of bottom pins on EOP passes
<tr valign=top> <td><b><tt>upWeaveFinalScan</tt></b>
<td>
<td>Int
<td>
<td>Begin EOP passes (Y-coord)
<tr valign=top> <td><b><tt>upWeaveFinalXStarts</tt></b>
<td>
<td>Int[ ]
<td>
<td>X-pass indices for EOP passes
<tr valign=top> <td><b><tt>upWeaveFinalYFeeds</tt></b>
<td>
<td>Int[ ]
<td>
<td>Y increments for EOP passes
<tr valign=top> <td><b><tt>upWeaveInitialPins</tt></b>
<td>
<td>Int[ ]
<td>
<td>Number of top pins on BOP passes
<tr valign=top> <td><b><tt>upWeaveInitialScan</tt></b>
<td>
<td>Int
<td>
<td>End BOP passes (Y coord)
<tr valign=top> <td><b><tt>upWeaveInitialXStarts</tt></b>
<td>
<td>Int[ ]
<td>
<td>X-pass indices for BOP passes
<tr valign=top> <td><b><tt>upWeaveInitialYFeeds</tt></b>
<td>
<td>int[ ]
<td>
<td>Y increments for BOP passes
<tr valign=top> <td><b><tt>upWeavePasses</tt></b>
<td>
<td>Int
<td>
<td>XPasses × YPasses
<tr valign=top> <td><b><tt>upWeaveXPasses</tt></b>
<td>
<td>Int
<td>
<td>Number of X passes
<tr valign=top> <td><b><tt>upWeaveXStarts</tt></b>
<td>
<td>Int[ ]
<td>
<td>X-pass indices for normal passes
<tr valign=top> <td><b><tt>upWeaveYFeeds</tt></b>
<td>
<td>Int[ ]
<td>
<td>Y increments for normal passes
<tr valign=top> <td><b><tt>upWeaveYOffset</tt></b>
<td>
<td>Int
<td>
<td>Number of blank or incomplete scans at BOP
<tr valign=top> <td><b><tt>upWeaveYPasses</tt></b>
<td>
<td>Int
<td>
<td>Number of X passes
<tr valign=top> <td><b><tt>upWhiteTransfer</tt></b>
<td>
<td>Float[ ]
<td>
<td>White transfer (monochrome devices!)
<tr valign=top> <td><b><tt>upWriteComponentCommands</tt></b>
<td>
<td>String[ ]
<td>
<td>Commands to write each component
<tr valign=top> <td><b><tt>upWroteData</tt></b>
<td>
<td>Bool (RO)
<td>
<td>Something (<b><tt>BeginJob</tt></b>) written to output
<tr valign=top> <td><b><tt>upXMoveCommand</tt></b>
<td>
<td>String
<td>
<td>X positioning command
<tr valign=top> <td><b><tt>upXStepCommand</tt></b>
<td>
<td>String
<td>
<td>Single step to the right
<tr valign=top> <td><b><tt>upYFlip</tt></b>
<td>
<td>Bool
<td>
<td>Flips output along the Y axis
<tr valign=top> <td><b><tt>upYMoveCommand</tt></b>
<td>
<td>String
<td>
<td>Y positioning command
<tr valign=top> <td><b><tt>upYStepCommand</tt></b>
<td>
<td>String
<td>
<td>Single step down
<tr valign=top> <td><b><tt>upYellowTransfer</tt></b>
<td>
<td>Float[ ]
<td>
<td>Yellow transfer
</table></blockquote>
<h3><a name="Uni_honors"></a><b><tt>uniprint</tt></b>'s Roll of Honor</h3>
<p>
I should mention all of the people who were involved in
<b><tt>stcolor</tt></b>'s evolution, but I've decided to start from scratch
here for <b><tt>uniprint</tt></b>:
<blockquote>
<dl>
<dt>John P. Beale
<dd>for testing the <b><tt>stc600</tt></b> modes
<dt>Bill Davidson
<dd>who triggered some weaving research and tested <b><tt>stc2s_h</tt></b>
<dt>L. Peter Deutsch
<dd>who triggered ease of configuration
<dt>Mark Goldberg
<dd>who prepared the <b><tt>stc500</tt></b> transfers
<dt>Scott F. Johnston and Scott J. Kramer
<dd>for testing the <b><tt>stc800</tt></b> modes
<dt>Martin Lottermoser
<dd>for his great commented H-P DeskJet driver
<dt>Helmut Riegler
<dd>for the BJC extension
<dt>Hans-Gerd Straeter
<dd>for some measured transfer curves and more
<dt>Uli Wortmann
<dd>for discussions and his <b><tt>cdj850</tt></b> driver
<dt>My family
<dd>for tolerating my printer-driver hacking
</dl>
</blockquote>
<address>
Gunther Hess<br>
Duesseldorfer Landstr. 16b<br>
D-47249 Duisburg<br>
Germany<br>
+49 203 376273 telephone (MET evening hours)<br>
<<a href="mailto:ghess@elmos.de">ghess@elmos.de</a>>
</address>
<h3><a name="Uni_weaving_howto"></a><tt>Uniprint</tt> weaving parameters howto</h3>
This section was contributed by Glenn Ramsey.<p>
<p>I wrote this because the documentation was very brief and I really struggled
with it for a while, but it is very simple once you understand what is going
on.
<p>This only describes how to work out the Y parameters, I haven't looked
at the X parameters yet.
<ol>
<li>
<b>Determine the nozzle geometry (upOutputPins)</b>
<p>
You need to know how many nozzles the printer has and the spacing between
them. Usually you can find this out from the printer manual, or the printer
supplier, but you may have to dissect a couple of printer output files
produced with the driver supplied with the printer. There is a utility
called escp2ras<a href="#escp2ras"><sup>*</sup></a> that will help with that.
Sometimes the term pin is used instead of nozzle but they mean the same thing.
<p>The number of nozzles will be the value assigned to the upOutputPins
parameter.
<p>Actually you don't have to print with all the pins available but for
the purpose of demonstration I'll assume that we are using them all.
<p>
<a name="escp2ras"></a>* escp2ras is available from Gunther Hess' page at <a href="http://www-md.e-technik.uni-rostock.de/ma/gunther/gs/index.html">http://www-md.e-technik.uni-rostock.de/ma/gunther/gs/index.html</a>
</li>
<p>
<li><b>Determine how many passes are required (upWeaveYPasses)</b>
<p>The number of passes required is going to depend on the required resolution
and the nozzle spacing.
<blockquote>
<tt>passes = resolution * nozzle spacing
</tt>
</blockquote>
This will be the value assigned to the upWeaveYPasses parameter.
<p>For example if the desired resolution is 360 dpi and the nozzles are
spaced at 1/90in then 360 * 1/90 = 4 passes are required. For 720 dpi 8
passes would be required. The printer would, of course, have to be capable
of moving the paper in increments of either 360 or 720 dpi too.
</li>
<p>
<li>
<b>Determine the normal Y feed increment (upWeaveYFeeds)</b>
<p>
You need to work out how much to feed the paper so that when the paper
has moved by one head length in however many passes you have then each
row space on the paper has been passed over by at least one nozzle. There
will be one feed value for each pass and the feed values must comply with
the following rules:
<blockquote>
<tt>
<p>sum of feeds = passes * nozzles
<br>feed%passes != 0 (feed is not exactly divisible by passes)
<br>sum of (nozzles - feed) = 0
</tt>
</blockquote>
<p>For example if passes=4 and nozzles=15, then sum of feeds=60. The feed
values could be 1,1,1,57 or 15,15,15,15 or 14,15,18,13.
<p>These values will be assigned to the upWeaveYFeeds parameter.
<p>You would need to experiment to see what combination looks best on the
printer.
<p>I found it convenient to draw several lines of nozzles and then move
them around to see how the different combinations would fill the paper.
A computer drawing tool makes this easier than pencil and paper (I used
Dia, a GNOME app). The number of nozzles would probably be be a good place
to start.
<p>Remember that if the number of passes is more than 1 then the feed increment
will be less than the nozzle spacing and <tt>passes × feed increment size</tt>
must equal the physical distance between each nozzle.
</li>
<p>
<li>
<b>Determine the beginning of page pins (upWeaveInitialPins)</b>
<p>
These values will be assigned to the upWeaveInitialPins parameter and are
the numbers of nozzles to operate in each of the initial passes at the top
of a page. The nozzles that the values refer to are the topmost nozzles
on the head, nearest the top margin. If the image doesn't start at the
top margin then uniprint doesn't use these feeds.
<p>I don't know a mathematical relation for this except that at least one
of the values must be the number of nozzles, but I'm sure that there must
be one. I used a graphical method, the description that follows refers
to the ascii diagram in below.
<p>Draw a line of nozzles for each pass arranged as they would be using
the normal Y feed increment determined in step 3. In the diagram below
this would be passes 5-8.
<p>Draw a line of nozzles that would print just before the first normal
pass. The feed increment for this pass will be close to and most likely
1 or 2 units less than the feed increment of the last normal pass. In the
example below this line is pass 4 and the feed increment is 13 whereas
the normal feed increment is 15.
<p>Draw each pass before that with a small feed increment so that if all
of the nozzles appearing above the first nozzle of the first normal pass
operate then all of the spaces will be filled. This feed increment is usually
1 except in cases where some jiggery pokery is going on to make the printer
print at an apparent higher resolution than the nozzle diameter.
<p>Now select the nozzles that will operate in each of theses initial passes
so that the paper is filled. In each pass the nozzles must be adjacent
to each other and at least one of the passes will have all the nozzles
operating. I suspect that for each combination of normal Y feed increments
there will only be one set of valid beginning of page increments.
</li>
</ol>
<h4>Example: stc.upp from Aladdin Ghostscript 6.01</h4>
15 nozzles spaced at 1/90 in, 360 dpi requires 4 passes.
<blockquote><tt><pre>
-dupWeaveYPasses=4
-dupOutputPins=15
-dupWeaveYFeeds="{15 15 15 15}"
-dupWeaveInitialYFeeds="{1 1 1 13}"
-dupWeaveInitialPins="{ 4 15 11 7}"
</pre></tt></blockquote>
The following diagram shows which nozzles operate during each pass.
<br>Passes 1-4 are beginning of page passes and passes 5-8 are normal passes.
<blockquote>
<p>x=nozzle operates, o=nozzle not used in this pass<tt></tt>
<p><tt> 1 2 3 4 5 6 7 8 - pass no</tt>
<br><tt>0 x</tt>
<br><tt>1 x</tt>
<br><tt>2 x</tt>
<br><tt>3 x</tt>
<br><tt>4 x</tt>
<br><tt>5 x</tt>
<br><tt>6 x</tt>
<br><tt>7 x</tt>
<br><tt>8 x</tt>
<br><tt>9 x</tt>
<br><tt>0 x</tt>
<br><tt>1 x</tt>
<br><tt>2 x</tt>
<br><tt>3 x</tt>
<br><tt>4 x</tt>
<br><tt>5 x</tt>
<br><tt>6 o x</tt>
<br><tt>7 x</tt>
<br><tt>8 x</tt>
<br><tt>9 x</tt>
<br><tt>0 o x</tt>
<br><tt>1 x</tt>
<br><tt>2 x</tt>
<br><tt>3 x</tt>
<br><tt>4 o x</tt>
<br><tt>5 x</tt>
<br><tt>6 x</tt>
<br><tt>7 x</tt>
<br><tt>8 o x</tt>
<br><tt>9 x</tt>
<br><tt>0 x</tt>
<br><tt>1 o x</tt>
<br><tt>2 o x</tt>
<br><tt>3 x</tt>
<br><tt>4 x</tt>
<br><tt>5 o x</tt>
<br><tt>6 o x</tt>
<br><tt>7 x</tt>
<br><tt>8 x</tt>
<br><tt>9 o x</tt>
<br><tt>0 o x</tt>
<br><tt>1 x</tt>
<br><tt>2 x</tt>
<br><tt>3 o x</tt>
<br><tt>4 o x</tt>
<br><tt>5 x</tt>
<br><tt>6 o
x</tt>
<br><tt>7 o x</tt>
<br><tt>8 o x</tt>
<br><tt>9 x</tt>
<br><tt>0 o
x</tt>
<br><tt>1 o x</tt>
<br><tt>2 o x</tt>
<br><tt>3 x</tt>
<br><tt>4 o
x</tt>
<br><tt>5 o x</tt>
<br><tt>6 o x</tt>
<br><tt>7 x</tt>
<br><tt>8 o
x</tt>
<br><tt>9 o x</tt>
<br><tt>0 x</tt>
<br><tt>1
x</tt>
<br><tt>2
x</tt>
<br><tt>3 x</tt>
<br><tt>4 x</tt>
<br><tt>5
x</tt>
<br><tt>6
x</tt>
<br><tt>7 x</tt>
<br><tt>8 x</tt>
<br><tt>9
x</tt>
<br><tt>0
x</tt>
<br><tt>1 x</tt>
<br><tt>2 x</tt>
<br><tt>3
x</tt>
<br><tt>4
x</tt>
<br><tt>5 x</tt>
<br><tt>6</tt>
<br><tt>7
x</tt>
<br><tt>8
x</tt>
<br><tt>9 x</tt>
<br><tt>0</tt>
<br><tt>1
x</tt>
<br><tt>2
x</tt>
<br><tt>3 x</tt>
<br><tt>4</tt>
<br><tt>5
x</tt>
<br><tt>6
x</tt>
<br><tt>7 x</tt>
<br><tt>8</tt>
<br><tt>9
x</tt>
<br><tt>0
x</tt>
<br><tt>1</tt>
<br><tt>2</tt>
<br><tt>3
x</tt>
<br><tt>4
x</tt>
<br><tt>5</tt>
<br><tt>6</tt>
<br><tt>7
x</tt>
<br><tt>8
x</tt>
<br><tt>9</tt>
<br><tt>0</tt>
<br><tt>1
x</tt>
<br><tt>2
x</tt>
<br><tt>3</tt>
<br><tt>4</tt>
<br><tt>5
x</tt>
<br><tt>6</tt>
<br><tt>7</tt>
<br><tt>8</tt>
<br><tt>9
x</tt>
<br><tt>0</tt>
<br><tt>1</tt>
<br><tt>2</tt>
<br><tt>3
x</tt>
<br><tt>4</tt>
<br><tt>5</tt>
<br><tt>6</tt>
<br><tt>7
x</tt>
</blockquote>
<p>These parameters would also work:
<blockquote><tt><pre>
-dupWeaveYPasses=4
-dupOutputPins=15
-dupWeaveYFeeds="{14 15 18 13}"
-dupWeaveInitialYFeeds="{1 1 1 13}"
-dupWeaveInitialPins="{ 4 11 7 15}"
</pre></tt></blockquote>
<p>
<hr>
<h3><a name="Uni_esc300"></a>Extension to <tt>uniprint</tt> for the Epson Stylus Color 300</h3>
This section was contributed by Glenn Ramsey.<p>
The Epson Stylus Color 300 uses a different command set to other Epson
Stylus Color printers that use the ESC/P2 language. As far as I can
tell its commands are a subset of ESC/P2. In ESC/P2 the colour to be
printed is selected by a 'set colour' command and then the data sent
is only printed in that colour until the colour is changed with another
'set colour' command. The Stylus Color 300 lacks this functionality.
The data sent to the printer maps directly to the ink nozzles and colour
of an output scan line in the printed output is determined by the position
of the scan line within the data. This means that the driver must know
how the nozzles are arranged and must format the output accordingly.
The extension adds a format that I have called EscNozzleMap and adds some
additional parameters to uniprint.<br>
<ul>
<li><b><tt>upOutputFormat</tt></b>selects the output method, and should be set to the value
<b><tt>/EscNozzleMap</tt></b> to select this format.
<blockquote>
<table cellpadding="0" cellspacing="0">
<tbody>
<tr valign="Top">
<td><b><tt>/EscNozzleMap</tt></b></td>
<td> </td>
<td>produces output for the Epson Stylus Color 300
</td>
</tr>
<tbody>
</table>
</blockquote>
</ul>
<blockquote>
<table cellpadding="0" cellspacing="0">
<tbody>
<tr>
<th colspan="5" bgcolor="#cccc00">
<hr><font size="+1"><b><tt>uniprint</tt></b> parameters for the
EscNozzleMap format</font>
<hr></th>
</tr>
<tr valign="Bottom">
<th align="Left">Parameter
</th>
<td>
</td>
<th align="Left">Type
</th>
<td>
</td>
<th align="Left">Use
</th>
</tr>
<tr>
<td colspan="5">
<hr></td>
</tr>
<tr valign="Top">
<td><b><tt>upNozzleMapRowsPerPass</tt></b></td>
<td>
</td>
<td>Int
</td>
<td>
</td>
<td>output rows to generate for each pass of the head
</td>
</tr>
<tr valign="Top">
<td><b><tt>upNozzleMapPatternRepeat</tt></b></td>
<td>
</td>
<td>Int
</td>
<td>
</td>
<td>no. of rows that correspond to the repeat pattern of the
nozzles
</td>
</tr>
<tr valign="Top">
<td><b><tt>upNozzleMapRowMask</tt></b></td>
<td>
</td>
<td>Int[]
</td>
<td>
</td>
<td>mask indicating the colour of the nozzles
</td>
</tr>
<tr valign="Top">
<td><b><tt>upNozzleMapMaskScanOffset</tt></b></td>
<td>
</td>
<td>Int[]
</td>
<td>
</td>
<td>mask indicating the physical position of the nozzles
</td>
</tr>
</tbody>
</table>
</blockquote>
<h4>A more detailed description of the new parameters</h4>
<ul>
<li><b><tt>upNozzleMapRowsPerPass</tt></b><br>
The number of rows of data that are required to address all nozzles for a
single pass of the head. There will always be this number of rows of output
data generated. I'd expect it to be the same as the total number of nozzles but
it wouldn't break the formatter if it wasn't. So if you wanted to print with
only the 10th nozzle then row 10 would contain data corresponding to the bit
pattern and all of the others would be padded with zeros.
</li>
<li><b><tt>upNozzleMapPatternRepeat</tt></b><br>
The number of nozzles in each repeated group on the printing head.
This parameter must correspond with the length of the upNozzleMapRowMask array.
</li>
<li><b><tt>upNozzleMapRowMask</tt></b><br>
An array of integers that defines the colour of the nozzles on the
head and whether the nozzles will be used to print. The array index
defines the row index for the nozzle in the output data
and the value defines the colour of the nozzle. The mapping
of colours to values is defined in the table below.
<blockquote>
<table cellpadding="0" cellspacing="0">
<tbody>
<tr valign="Bottom">
<th align="Left">colour
</th>
<td>
</td>
<th align="center">mask value
</th>
</tr>
<tr>
<td colspan="5">
<hr></td>
</tr>
<tr valign="Top" align="middle">
<td><b><tt>K</tt></b></td>
<td>
</td>
<td>1
</td>
</tr>
<tr valign="Top" align="middle">
<td><b><tt>C</tt></b></td>
<td>
</td>
<td>2
</tr>
<tr valign="Top" align="middle">
<td><b><tt>M</tt></b></td>
<td>
</td>
<td>3
</td>
</tr>
<tr valign="Top" align="middle">
<td><b><tt>Y</tt></b></td>
<td>
</td>
<td>4
</td>
</tr>
<tr valign="Top" align="middle">
<td><b><tt>no data</tt></b></td>
<td>
</td>
<td>0
</td>
</tr>
</tbody>
</table>
</blockquote>
A value of 0 means that the nozzle is not used and the row in the output data will be
padded with zeros.<br>
</li>
<li><b><tt>upNozzleMapMaskScanOffset</tt></b><br>
An array of integers that defines the physical position of the nozzles relative
to the first nozzle in the repeated group. The relative distance is measured in
printed line widths and will be different for different printing resolutions.
This parameter is used because the physical spacing of the nozzles may not
correspond to their mapping in the output data. For example the ESC300 has nozzles
physically arranged something like this:
<table>
<tr>
<td bgcolor="#00ffff">
</td>
<td bgcolor="#ffff00">
</td>
<td bgcolor="#000000">
</td>
<td bgcolor="#ff00ff">
</td>
<td bgcolor="#000000">
</td>
<td>
</td>
<td bgcolor="#000000">
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td bgcolor="#00ffff">
</td>
<td bgcolor="#ffff00">
</td>
<td bgcolor="#000000">
</td>
<td bgcolor="#ff00ff">
</td>
<td bgcolor="#000000">
</td>
<td>
</td>
<td bgcolor="#000000">
</td>
<td bgcolor="#ffffff">
</td>
</tr>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td bgcolor="#00ffff">
</td>
<td bgcolor="#ffff00">
</td>
<td bgcolor="#000000">
</td>
<td bgcolor="#ff00ff">
</td>
<td bgcolor="#000000">
</td>
<td>
</td>
<td bgcolor="#000000">
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td bgcolor="#00ffff">
</td>
<td bgcolor="#ffff00">
</td>
<td>etc ...
</td>
<tr>
</tr>
</table>
There is a one nozzle width space between the last two nozzles in each group.
In the output data the data for the last nozzle in the group would be in row 5
(numbering starts at 0) but the nozzle is physically positioned at 6 spaces from
the first nozzle.
</ul>
<h4>Example 1 - Epson Stylus Color 300 - 360 dpi colour</h4>
<blockquote><pre>
-dupWeaveYPasses=6
-dupOutputPins=11
-dupWeaveYFeeds="{ 11 11 11 11 11 11 }"
-dupWeaveInitialYFeeds="{ 1 1 1 1 1 7 }"
-dupWeaveInitialPins="{ 2 11 9 7 5 3 }"
-dupNozzleMapRowsPerPass=64
-dupNozzleMapPatternRepeat=6
-dupNozzleMapRowMask="{ 2 4 1 3 0 0 }"
-dupNozzleMapMaskScanOffset="{ 0 1 2 3 0 0 }"
</pre></blockquote>
The weaving parameters are the same as for any other uniprint driver
but they must be consistent with the nozzle map parameters. In this printer
the coloured nozzles are spaced at 1/60" so 6 passes are required for 360
dpi resolution.
<p>
In the example there are 64 rows of data required for each head pass. Each
row must be completely filled with data for each pass so if certain nozzles
do not print in the pass then the rows for those nozzles will be padded
with zeroes.
<P>
The row mask translates to "C Y K M 0 0" so in the output data rows 0,7,13,...
will contain data for cyan, rows 1,8,14,... will contain data for yellow, etc. Rows 4,10,16,...
and 5, 11,15,... will always be padded with zeroes. The <i>upNozzleMapPatternRepeat</i>
parameter defines the length of the mask.
<p>
The row mask is repeated for each group of <i>upNozzleMapPatternRepeat</i> rows
in the output data. In this case there are 64 rows so there will be 10 groups
of "C Y K M 0 0" followed by "C Y K M" which is equivalent to 11 output
pins.
<P>
The <i>upNozzleMaskScanOffset</i> array indicates how the data from the scan
buffer is mapped to the output data. The data is presented to the formatter
as a buffer of four colour scanlines. The index of the scanline being printed,
lets call it y, always corresponds, in this example, to the physical position of
the cyan nozzle but since the nozzles are not on the same horizontal
line then the other colours for the current pass must come from other
scanlines in the scan buffer. The example is { 0 1 2 3 0 0 }, this means that
when printing a 4 colour image the magenta data would come from scanline y+3,
the black from scanline y+2, etc. It would have been possible in this case
to use the array index instead of the <i>upNozzleMaskScanOffset</i> parameter
however the parameter is necessary to be able to use the full capability of the
printer in black only mode.
<h4>Example 2 - Epson Stylus Color 300 - 180 dpi black only</h4>
<blockquote>
<pre>
-dupMargins="{ 9.0 39.96 9.0 9.0}"
-dupWeaveYPasses=1
-dupOutputPins=31
-dupNozzleMapRowsPerPass=64
-dupNozzleMapPatternRepeat=6
-dupNozzleMapRowMask="{ 0 0 1 0 1 1}"
-dupNozzleMapMaskScanOffset="{ 0 0 0 0 1 2 }"
</pre>
</blockquote>
In this example there is no weaving.
<p>
The ESC300 has black nozzles evenly physically arranged as K K K but the data must
be sent to the printer as 00K0KK. This is handled by the <i>upNozzleMapRowMask</i>
and <i>upNozzleMaskScanOffset</i> arrays. The <i>upNozzleMapRowMask</i> array is
{ 0 0 1 0 1 1} which translates to { 0 0 K 0 K K } so rows 0, 1 and 3 will always
contain zeros and the other rows will contain data.
<p>
The <i>upNozzleMaskScanOffset</i> array
in this case is { 0 0 0 0 1 2 } so if the data for the 1st nozzle comes from row
y in the scan buffer then the data for the 2nd and 3rd nozzles will come from rows
y+1 and y+2.
<h4>Example 3 - Epson Stylus Color 300 - 360 dpi black only</h4>
<blockquote>
<pre>
-dupWeaveYPasses=2
-dupOutputPins=31
-dupWeaveYFeeds="{31 31}"
-dupWeaveInitialYFeeds="{1 31}"
-dupWeaveInitialPins="{16 31}"
-dupNozzleMapRowsPerPass=64
-dupNozzleMapPatternRepeat=6
-dupNozzleMapRowMask="{ 0 0 1 0 1 1}"
-dupNozzleMapMaskScanOffset="{ 0 0 0 0 2 4 }"
</pre>
</blockquote>
In this example 2 weave passes are required to achieve the desired resolution.
<p>
The <i>upNozzleMaskScanOffset</i> array in this case is { 0 0 0 0 2 4 } because
there are two weave passes so if the data for the first nozzle comes from row y
in the scan buffer then the data for the 2nd and 3rd nozzles must come from rows
y+(1*2) and y+(2*2).
<p>
<address>
Glenn Ramsey<br>
glennr at users.sourceforge.net<br>
February 2001
</address>
<br>
<hr>
<h2><a name="SPARCprinter"></a>Sun SPARCprinter</h2>
<p>
This section was contributed by Martin Schulte.
<p>
With a SPARCprinter you always buy software that enables you to do
PostScript printing on it. A page image is composed on the host, which
sends a bitmap to the SPARCprinter through a special SBUS video interface.
So the need for a Ghostscript interface to the SPARCPrinter seems low, but
on the other hand, Sun's software prints some PostScript drawings
incorrectly: some pages contain a thin vertical line of rubbish, and on
some Mathematica drawings the text at the axes isn't rotated. Ghostscript,
however, gives the correct results. Moreover, replacing proprietary
software should never be a bad idea.
<p>
The problem is that there has yet been no effort to make the SPARCPrinter
driver behave like a BSD output filter. I made my tests using the script
shown here.
<h3><a name="SPARC_install"></a>Installation</h3>
<p>
Add <b><tt>sparc.dev</tt></b> to <b><tt>DEVICE_DEVS</tt></b> and compile
Ghostscript as described in the documentation on <a href="Make.htm">how to
build Ghostscript</a>. Afterwards you can use the following script as an
example for printing after modifying it with the right pathnames --
including for <b>{GSPATH}</b> the full pathname of the Ghostscript
executable:
<blockquote>
<pre>outcmd1='/vol/local/lib/troff2/psxlate -r'
outcmd2='<b><em>{GSPATH}</em></b> -sDEVICE=sparc -sOUTPUTFILE=/dev/lpvi0 -'
if [ $# -eq 0 ]
then
$outcmd1 | $outcmd2
else
cat $* | $outcmd1 | $outcmd2
fi
</pre></blockquote>
<h3><a name="SPARC_problems"></a>Problems</h3>
<p>
Since <b><tt>/dev/lpi</tt></b> can be opened only for exclusive use, if
another job has it open (engine_ctl_sparc or another Ghostscript are the
most likely candidates), Ghostscript stops with "Error: /invalidfileaccess
in --.outputpage--"
<p>
In case of common printer problems like being out of paper, a warning
describing the reason is printed to stdout. The driver tries access again
each five seconds. Due to a problem with the device driver (in the kernel)
the reason for printer failure isn't always reported correctly to the
program. This is the case, for instance, if you open the top cover (error
E5 on the printer's display). Look at the display on the printer itself if
a "Printer problem with unknown reason" is reported. Fatal errors cause
the print job to be terminated.
<hr>
<h2><a name="Apple"></a>Apple dot matrix printer</h2>
<p>
This section was contributed by Mark Wedel
<<a href="mailto:master@cats.ucsc.edu">master@cats.ucsc.edu</a>>.
<p>
The Apple Dot Matrix Printer (DMP) was a parallel predecessor to the
Imagewriter printer. As far as I know, Imagewriter commands are a superset
of the Dot Matrix printer's, so the driver should generate output that can
be printed on Imagewriters.
<p>
To print images, the driver sets the printer for unidirectional printing
and 15 characters per inch (cpi), or 120dpi. It sets the line feed to 1/9
inch. When finished, it sets the printer to bidirectional printing,
1/8-inch line feeds, and 12 cpi. There appears to be no way to reset the
printer to initial values.
<p>
This code does not set for 8-bit characters (which is required). It also
assumes that carriage return-newline is needed, and not just carriage
return. These are all switch settings on the DMP, and I have configured
them for 8-bit data and carriage return exclusively. Ensure that the Unix
printer daemon handles 8-bit (binary) data properly; in my SunOS 4.1.1
<b><tt>printcap</tt></b> file the string "<b><tt>ms=pass8,-opost</tt></b>"
works fine for this.
<p>
Finally, you can search <b><tt>devdemp.c</tt></b> for
"<b><tt>Init</tt></b>" and "<b><tt>Reset</tt></b>" to find the strings that
initialize the printer and reset things when finished, and change them to
meet your needs.
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<p>
<small>Copyright © 1996, 2000 Aladdin Enterprises.
All rights reserved.</small>
<p>
This software is provided AS-IS with no warranty, either express or
implied.
This software is distributed under license and may not be copied,
modified or distributed except as expressly authorized under the terms
of the license contained in the file LICENSE in this distribution.
For more information about licensing, please refer to
http://www.ghostscript.com/licensing/. For information on
commercial licensing, go to http://www.artifex.com/licensing/ or
contact Artifex Software, Inc., 101 Lucas Valley Road #110,
San Rafael, CA 94903, U.S.A., +1(415)492-9861.
<p>
<small>Ghostscript version 7.05, 22 April 2002
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