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<h2><b>spectro/chartread</b></h2>
<h3>Summary</h3>
Read a printer test chart using an instrument, to create a <a
href="File_Formats.html#.ti3">.ti3</a> data file. The type of
instrument is determined by the communication port
selected.<br>
<br>
<span style="font-weight: bold;">chartread</span> can also be used
to
read transmission values, and to read display values manually.<br>
<h3>Usage</h3>
<small><span style="font-family: monospace;">chartread [-options]
outfile</span><br style="font-family: monospace;">
<span style="font-family: monospace;"> </span><a
style="font-family: monospace;" href="#v">-v</a><span
style="font-family: monospace;">
Verbose
mode</span><br style="font-family: monospace;">
<span style="font-family: monospace;"> </span><a
style="font-family: monospace;" href="#c">-c listno</a><span
style="font-family: monospace;">
Set communication port from the following list (default 1)</span><br
style="font-family: monospace;">
<span style="font-family: monospace;"> </span><a
style="font-family: monospace;" href="#t">-t</a><span
style="font-family: monospace;">
Use
transmission
measurement mode<br>
</span></small><small><span style="font-family: monospace;"> </span><a
style="font-family: monospace;" href="#d">-d</a><span
style="font-family: monospace;">
Use
display
measurement
mode (white Y relative results)</span></small><small><span
style="font-family: monospace;"></span></small><small><span
style="font-family: monospace;"><br>
</span></small><font size="-1"><span style="font-family:
monospace;"><a href="#y">-y X</a>
Display type - instrument specific list to choose from.</span></font><br>
<small><span style="font-family: monospace;"> </span><a
style="font-family: monospace;" href="#e">-e</a><span
style="font-family: monospace;">
Use
emissive
measurement
mode (absolute results)<br>
</span></small><small><span style="font-family: monospace;"> </span><a
style="font-family: monospace;" href="#p">-p</a><span
style="font-family: monospace;">
Measure
patch
by
patch rather than strip</span></small><br>
<small><span style="font-family: monospace;"></span> <a
style="font-family: monospace;" href="#x">-x [lx]</a><span
style="font-family: monospace;">
Take
external
values,
either L*a*b* (-xl) or XYZ (-xx).</span><br style="font-family:
monospace;">
<span style="font-family: monospace;"> </span><a
style="font-family: monospace;" href="#n">-n</a><span
style="font-family: monospace;">
Don't
save spectral information (default saves
spectral)<br>
</span></small><small><span style="font-family: monospace;"> </span><a
style="font-family: monospace;" href="#l">-l</a><span
style="font-family: monospace;">
Save CIE as D50 L*a*b* rather than XYZ<br>
</span></small><small><span style="font-family: monospace;"> </span><a
style="font-family: monospace;" href="#L">-L</a><span
style="font-family: monospace;">
Save CIE as D50 L*a*b* as well as XYZ</span></small><br>
<small><span style="font-family: monospace;"> <a href="#r">-r</a>
Resume
reading
partly
read chart<br>
<a href="#I">-I</a>
file.cal Override
calibration
info from .ti2 in resulting .ti3<br>
</span></small><font size="-1"><span style="font-family:
monospace;"><a href="#F">-F filter</a>
Set
filter
configuration:<br>
n
None<br>
p
Polarising
filter<br>
6
D65<br>
u
U.V.
Cut</span></font><small><span style="font-family: monospace;"></span><span
style="font-family: monospace;"></span></small><br>
<font size="-1"><span style="font-family: monospace;"> </span><a
style="font-family: monospace;" href="#N">-N</a><span
style="font-family: monospace;">
Disable
auto
calibration of instrument<br>
</span></font><font size="-1"><span style="font-family:
monospace;"> </span><a style="font-family: monospace;"
href="#B">-B</a><span style="font-family: monospace;">
Disable
auto
bi-directional strip recognition</span></font><br>
<font size="-1"><span style="font-family: monospace;"> </span><a
style="font-family: monospace;" href="#H">-H</a><span
style="font-family: monospace;">
Use
high
resolution spectrum mode (if available)<br>
</span></font><font size="-1"><span style="font-family:
monospace;"> </span></font><font size="-1"><span
style="font-family: monospace;"><a href="#X1">-X file.ccmx</a>
Apply Colorimeter Correction Matrix</span></font><br>
<span style="font-family: monospace;"> <a href="#X2">-X
file.ccss</a>
Use
Colorimeter
Calibration
Spectral
Samples
for calibration</span><br style="font-family: monospace;">
<span style="font-family: monospace;"> <a href="#X3">-X N</a>
0: Technology (Display description)</span><br style="font-family:
monospace;">
<span style="font-family: monospace;">
1: etc.</span><br>
<small><span style="font-family: monospace;"> </span><a style="
font-family: monospace;" href="#Q">-Q observ</a><span
style="font-family: monospace;">
Choose CIE Observer for
spectral data or CCSS instrument:</span><br style="font-family:
monospace;">
<span style="font-family: monospace;">
</span></small><small><span
style="font-family: monospace;">1931_2 </span></small><small><span
style="font-family: monospace;"> (def.)</span></small><small><span
style="font-family: monospace;">, 1964_10, S&B 1955_2, shaw,
J&V 1978_2</span></small><small><span style="font-family:
monospace;"></span></small><font size="-1"><span
style="font-family: monospace;"></span></font><br>
<font size="-1"><span style="font-family: monospace;">
<a href="#T">-T ratio</a>
Modify
strip
patch
consistency tolerance by ratio (if available)<br>
</span></font><font size="-1"><span style="font-family:
monospace;"> <a href="#S">-S</a>
Suppress
wrong
strip
& unexpected value warnings</span></font><br>
<font size="-1"><span style="font-family: monospace;"> <a
href="#W">-W
n|h|x</a>
Override
serial port flow control: n = none, h = HW, x = Xon/Xoff</span></font><br
style="font-family: monospace;">
<small><span style="font-family: monospace;"></span><small
style="font-family: monospace;"> <a href="#D">-D [level]</a>
Print debug
diagnostics to
stderr</small><br style="font-family: monospace;">
<span style="font-family: monospace;"> </span><a
style="font-family: monospace;" href="#p1"><i>inoutfile</i></a><span
style="font-family: monospace;">
Base
name
for
input[</span><a style="font-family: monospace;"
href="File_Formats.html#.ti2">.ti2</a><span style="font-family:
monospace;">]/output[</span><a style="font-family: monospace;"
href="File_Formats.html#.ti3">.ti3</a><span style="font-family:
monospace;">] file</span></small>
<br>
<h3>Usage Details</h3>
<a name="v"></a>The <b>-v</b> flag causes extra information to be
printed out during chartread
operation.<br>
<br>
<a name="c"></a>Normally instruments are connected via a serial
communication port, and the
port used should be selected by supplying the correct parameter to
the <b>-c</b>
flag. If you invoke <span style="font-weight: bold;">chartread</span>
so as to display the usage
information (i.e. "chartread -?" or "chartread --"), then the
discovered
serial ports will be listed on Windows and Mac OSX systems.<br>
<br>
<a name="t"></a>If using an Xrite DTP41T, and printing onto
transparent
or back lit media,
use the <b>-t</b> flag to operate the instrument in transparency
mode.
If using a Spectrolino or Eye-One Pro (handheld), this triggers a
fake
transparency
mode, that uses a separate backlight (such as a light box).
The
instrument will be used to calibrate the level of backlight, and use
this to compute the transparency of the test chart samples. Note
that
for good transparency values, the backlight level needs to be
neither
too bright not too dark, should ideally be incandescent rather than
fluorescent (since fluorescent lights often have big dips in their
spectrum), and ideally should be of uniform brightness over the
measurement area. If using the SpectroScanT, the <span
style="font-weight: bold;">-t</span> flag operates the instrument
in
transparency mode, each reading being manually triggered.<br>
<br>
<a name="d"></a>The <span style="font-weight: bold;">-d</span> flag
allows measuring
in display mode using
instruments that
support this mode, with the brightness normalized to the white patch
value
in the test chart. While the brightness values are then
relative to the white, the readings are otherwise absolute. This
corresponds to the raw ICC absolute readings created by <a
href="dispread.html">dispread</a>, and is the mode that should be
used
for creating a normal display ICC profile using manual, spot by spot
readings. This can be useful if the display cannot be driven
directly
by the computer, but can be made manually to display the test
charts.<br>
<br>
<a name="y"></a> The <span style="font-weight: bold;">-y</span>
flag allows setting the Display Type. Most colorimeters need this
parameter set to operate correctly. The selection typically
determines two aspects of of the instrument operation: <span
style="font-weight: bold;">1)</span> It may set the measuring mode
to suite <a
href="http://en.wikipedia.org/wiki/Comparison_of_display_technology"><span
style="font-weight: bold;">refresh</span> or <span
style="font-weight: bold;">non-refresh</span> displays</a>.
Typically only LCD (Liquid Crystal) displays have a non-refresh
nature. <span style="font-weight: bold;">2)</span> It may select an
instrument calibration matrix suitable for a particular display
type. The selections available depends on the type and model of
instrument, and a list of the options for the discovered instruments
will be shown in the <a href="ArgyllDoc.html#CmdLine">usage</a>
information. For more details on what particular instruments support
and how this works, see <a href="instruments.html">Operation of
particular instruments</a>.<br>
<br>
<a name="e"></a> If using an instrument that supports an emissive
measurement mode (such as the Spectrolino), then the <span
style="font-weight: bold;">-e</span> flag enables this measurement
mode, and the values recorded will be absolute XYZ values. This can
be
used for media such as backlit film, measuring it on a lightbox, so
as
to capture the actual illumination characteristics of that
particular
media. An adaptive integration time will be used in devices that
support it. <br>
<br>
<a name="p"></a> The <span style="font-weight: bold;">-p</span>
flag
causes chartread to use a spot read mode for an instrument, even if
it
is capable of faster chart reading modes such as strip reading. This
can be useful if strip measurement patch recognition is not reliable
for certain media.<br>
<br>
<a name="x"></a> The <span style="font-weight: bold;">-x</span>
flag
causes chartread to expect values to be entered for each reading,
rather than using an instrument to do the measurements. This
mode
is ideal if your instrument is not supported by Argyll. Either XYZ
or
L*a*b* values can be entered, depending on what option follows <span
style="font-weight: bold;"><span style="font-weight: bold;">-l</span></span>,
<span style="font-weight: bold;">-lx</span> to specify XYZ values,
or <span style="font-weight: bold;">-ll</span> to specify L*a*b*
values. XYZ
values are expected to be scaled to a maximum of 100. It is possible
to
navigate about the test values being measured, so as to do them in
any
order, as well as re-do values, in case of any mistakes.<br>
<br>
<a name="n"></a> <span style="font-weight: bold;">-n</span> By
default
spectral information as well as D50
standard observer XYZ values
will be recorded for each test patch, when such readings are
available
from a device. The spectral readings allow for
choosing
a non-standard viewing illuminant, a non-standard observer model, or
the use of the Fluorescent Paper Whitener Additive
compensation
when creating the profile. If the spectral readings are not needed,
then
prinread operation can be speeded up by specifying the <b>-n</b>
flag.<br>
<br>
<a name="l"></a> <span style="font-weight: bold;">-l</span> By
default
D50
standard observer XYZ values
will be recorded for each test patch, but if the <span
style="font-weight: bold;"><span style="font-weight: bold;">-l</span></span>
flag is used, D50 L*a*b* values will be recorded instead.<br>
<br>
<a name="L"></a> <span style="font-weight: bold;">-L</span> By
default
D50
standard observer XYZ values
will be recorded for each test patch, but if the <span
style="font-weight: bold;"><span style="font-weight: bold;">-L</span></span>
flag is used, XYZ <span style="font-weight: bold;">and </span>D50
L*a*b*
values will be recorded.<br>
<br>
<a name="r"></a> <span style="font-weight: bold;">-r</span> By
default
chartread reads the chart from scratch each time. When reading a
chart
using a strip instrument or patch by patch you can choose to finish
chartread without reading all the patches, and whatever patches have
been read will be saved to the output .ti3 file. You can then <span
style="text-decoration: underline;">resume</span> reading the
patches
by using the <span style="font-weight: bold;">-r</span> flag, in
which
case chartread will read the .ti3 file and set the patches to those
previously read values, allowing any unread patches to then be read,
or
to re-read previously read patches.<br>
<br>
<a name="I"></a> <span style="font-weight: bold;">-I</span> <span
style="font-style: italic;">file.cal</span> Normally per
channel
calibration curves are added to the .ti2 file using the <span
style="font-weight: bold;">printtarg -K</span> or <span
style="font-weight: bold;">-I</span> options, so that they will be
passed on to the .ti3 file by <span style="font-weight:
bold;">chartread</span>,
so
that
<span style="font-weight: bold;">colprof</span> is able to
correctly compute total ink limits. Where the calibration is being
applied in a workflow with native calibration capability<small><span
style="font-family: monospace;"></span></small> though, it is
sometimes convenient to re-use a profile chart with different
calibration curves without going through the process of using <span
style="font-weight: bold;">printtarg</span> to re-create it. This
would mean though, that the calibration information and subsequent
ink
limit calculations wouldn't be accurate. To overcome this and allow
such a scenario, the <span style="font-weight: bold;">chartread -I</span>
parameter allows overriding the .ti2 calibration curves placed in
the
resulting .ti3 file with the actual calibration that was used for
that
particular print.<br>
<br>
<a name="F"></a>The <b>-F</b> options allows configuring the
instrument to have a particular filter fitted to it. Some
instruments
(i.e. the Gretag Spectrolino) allow the fitting of various filters,
such as a polarizing filter, D65 illuminant simulation, or Ultra
Violet
Cut filter, and this option allows the instrument to be configured
appropriately.<br>
<br>
<a name="N"></a> <span style="font-weight: bold;">-N</span> Many
instruments automatically ask for an instrument
calibration before each set of readings. Sometimes this can be
awkward
if the instrument is being mounted in some sort of measuring jig, or
annoying if several sets of readings are being taken in quick
succession. The -<span style="font-weight: bold;">N</span>
suppresses
this automatic calibration (if possible), causing the previous
calibration recorded in the instrument or on the host computer. It
is
advisable to only use this option on the second and subsequent
measurements in a single session.<br>
<br>
<a name="B"></a> <span style="font-weight: bold;">-B</span> Some
strip
instruments (i.e.. Eye-One Pro, Color Munki) when used
with Argyll will automatically recognize a strip when read in the
reverse direction by matching the patch readings against their
expected values. If the randomized patch layout has not been used,
or
the expected values are not known accurately
enough, this may cause erroneous reverse recognition, so the <span
style="font-weight: bold;">-<span style="font-weight: bold;">B</span></span>
flag allows this to be turned off, forcing strips to only be read in
the forward direction.<br>
<br>
<a name="H"></a> The -<span style="font-weight: bold;">H</span>
option
turns on high resolution spectral mode, if the instrument supports
it.
See <a href="instruments.html">Operation of particular instruments</a>
for more details.<br>
<br>
<a name="X1"></a> The -<span style="font-weight: bold;">X <span
style="font-style: italic;">file.ccmx</span></span> option reads
a <a href="File_Formats.html#.ccmx">Colorimeter Correction Matrix</a>
from the given file, and applies it to the colorimeter instruments
readings. This can improve a colorimeters accuracy for a particular
type of display. A list of contributed <span style="font-weight:
bold;">ccmx</span> files is <a href="ccmxs.html">here</a>.<br>
<br>
<a name="X2"></a> The -<span style="font-weight: bold;">X <span
style="font-style: italic;">file.ccss</span></span> option reads
a <a href="File_Formats.html#.ccss">Colorimeter Calibration
Spectral Sample</a>
from the given file, and uses it to set the colorimeter instruments
calibration. This will only work with colorimeters that rely on
sensor
spectral sensitivity calibration
information (ie. the X-Rite <span style="font-weight: bold;">i1d3</span>,
or the DataColor <span style="font-weight: bold;">Spyder4</span>).This
can
improve
a
colorimeters accuracy for a particular
type of display.<br>
<br>
<a name="X3"></a> The -<span style="font-weight: bold;">X <span
style="font-style: italic;">N</span></span> option selects a <a
href="File_Formats.html#.ccss">Colorimeter Calibration Spectral
Sample</a> from the list of installed ccss files, rather than
specifying a specific ccss files as in the above usage. The CCSS
file that came with the i1d3 colorimeters can be installed using <a
href="i1d3ccss.html">i1d3ccss</a>, or one can be created and
installed using <a href="ccxxmake.html">ccxxmake</a>.<br>
<br>
<a name="T"></a> The -<span style="font-weight: bold;">T ratio</span>
argument modifies the patch consistency tolerance threshold for some
strip reading instruments (ie. the Eye-One Pro). In recognizing
patches
in a strip, an instrument may take multiple readings as the strip is
read, and then divide the readings up into each patch. It may then
check the consistency of the multiple readings corresponding to each
patch, and reject the measurement if they are too inconsistent. For
some media (ie. a coarser screens, fabric etc.) the default
tolerance
may be unreasonably tight, so the <span style="font-weight: bold;">-T
ratio</span> argument can be used to modify this criteria. To
loosen
the tolerance, use a number greater than 1.0 (ie. 1.5, 2.0).<br>
<br>
<a name="Q"></a> The <b>-Q</b> flag allows specifying a tristimulus
observer for a colorimeter when using CCSS instrument calibration
capability. The following choices are available:<br>
<b> 1931_2</b> selects the standard CIE 1931 2 degree
observer. The default.<br>
<b>1964_10</b> selects the standard CIE 1964 10 degree
observer.<br>
<b>1955_2</b> selects the Stiles and Birch 1955 2 degree
observer<br>
<b>1978_2 </b>selects the Judd and Voss 1978 2 degree
observer<br>
<b>shaw</b> selects the Shaw and Fairchild 1997 2 degree
observer<br>
<br>
<a name="S"></a>The <b>-S</b> flag causes the normal "wrong strip"
and
"unexpected value" warnings to be suppressed. There may be a lot of
these warnings if the expected patch value in the .ti2 file is in
fact
far from the values actually being measured. It is probably
advisable
to also use the <span style="font-weight: bold;">-B</span> flag if
warnings are turned off, since many warnings indicate that the
expected
values are not to be relied on. With warnings suppressed, greater
care
must be taken to read the correct strip.<br>
<br>
<a name="W"></a>The <b>-W</b> <span style="font-weight: bold;">n|h|x</span>
parameter overrides the default serial communications
flow control setting. The value <span style="font-weight: bold;">n</span>
turns all flow control off, <span style="font-weight: bold;">h</span>
sets hardware handshaking, and <span style="font-weight: bold;">x</span>
sets Xon/Xoff handshaking. This commend may be useful in workaround
serial communications issues with some systems and cables. <br>
<br>
<a name="D"></a>The <b>-D</b> flag causes communications
and other instrument diagnostics to be printed to stdout. A level
can
be set between 1 .. 9, that may give progressively more verbose
information, depending on the instrument. This can be useful in
tracking
down why an instrument can't connect.<br>
<br>
<a name="p1"></a> The <i>inoutfile</i> parameters should be the
base
name of the .ti2 file,
and chartread will output an .ti3 that has the same basename and the
.ti3
extension. If the incoming .ti2 file contains per-channel
calibration
curves, these will be passed through to the .ti3 so that accurate
ink
limits can be computed during profiling.<br>
<br>
<hr style="width: 50%; height: 2px;">
<h3>Discussion</h3>
For information about the operation of different instruments, see <a
href="instruments.html">Operation of particular instruments</a>.<br>
<br>
<br>
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