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<h2><b>spectro/spotread</b></h2>
<h3>Summary</h3>
Use an instrument to read a single color value. This can be a useful
diagnostic aid. The type of instrument is determined by the
communication port selected.
<h3>Usage Summary</h3>
<small><span style="font-family: monospace;">spotread [-options]
[logfile]</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><span
style="font-family: monospace;"> </span></small><small><span
style="font-family: monospace;"></span><a style=" font-family:
monospace;" href="#s">-s</a><span style="font-family:
monospace;">
Print spectrum for each reading.</span></small><br
style="font-family: monospace;">
<small><span style="font-family: monospace;"></span><span
style="font-family: monospace;"> </span><a
style="font-family: monospace;" href="#S">-S</a><span
style="font-family: monospace;">
Plot the spectrum in a graph window.</span><br
style="font-family: monospace;">
<span style="font-family: monospace;"> </span><a
style="font-family: monospace;" href="#c">-c comport</a><span
style="font-family: monospace;">
Set COM port, 1..4 (default 1)</span><span style="font-family:
monospace;"></span><span style="font-family: monospace;"><br
style="font-family: monospace;">
</span><span style="font-family: monospace;"> </span><a
style="font-family: monospace;" href="#t">-t</a><span
style="font-family: monospace;">
Use transmission measurement mode</span><br
style="font-family: monospace;">
<span style="font-family: monospace;"> </span><a
style="font-family: monospace;" href="#d">-d</a><span
style="font-family: monospace;">
Use display measurement mode (absolute results)<br>
</span></small><small><span style="font-family: monospace;"> </span><a
style="font-family: monospace;" href="#db">-db</a><span
style="font-family: monospace;">
Use display white brightness relative measurement mode<br>
</span></small><small><span style="font-family: monospace;"> </span><a
style="font-family: monospace;" href="#dw">-dw</a><span
style="font-family: monospace;">
Use display white relative measurement mode<br>
</span></small><small><span style="font-family: monospace;"> </span><a
style=" font-family: monospace;" href="#p">-p</a><span
style="font-family: monospace;">
Use projector measurement mode (absolute results)<br>
</span></small><small><span style="font-family: monospace;"> </span><a
style=" font-family: monospace;" href="#pb">-pb</a><span
style="font-family: monospace;">
Use </span></small><small><span style="font-family: monospace;">projector</span></small><small><span
style="font-family: monospace;"> white brightness relative
measurement mode<br>
</span></small><small><span style="font-family: monospace;"> </span><a
style=" font-family: monospace;" href="#pw">-pw</a><span
style="font-family: monospace;">
Use </span></small><small><span style="font-family: monospace;">projector</span></small><small><span
style="font-family: monospace;"> white relative measurement mode</span></small><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)</span></small><br>
<small><span style="font-family: monospace;"> </span><a
style="font-family: monospace;" href="#a">-a</a><span
style="font-family: monospace;">
Use ambient measurement mode (absolute results)<br>
<a href="#f">-f</a>
Use ambient flash measurement mode (absolute results)<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
style="font-family: monospace;">
<small><span style="font-family: monospace;"></span><span
style="font-family: monospace;"> </span><a
style="font-family: monospace;" href="#i">-i illum</a><span
style="font-family: monospace;">
Choose illuminant for
print/transparency spectral data:</span><br style="font-family:
monospace;">
<span style="font-family: monospace;">
A,
D50
(def.),
D65, F5, F8, F10 or file.sp</span><br style="font-family:
monospace;">
<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;"><br>
<a href="#F">-F filter</a>
Set filter configuration:<br>
n
None<br>
p
Polarising filter<br>
6
D65<br>
u
U.V. Cut<br>
<a href="#E">-E extrafilterfile</a>
Apply extra filter compensation file<br>
</span></font><font size="-1"><span style="font-family:
monospace;"> <a href="#x">-x</a>
Display Yxy instead of Lab<br>
</span></font><font size="-1"><span style="font-family:
monospace;"> <a href="#h">-h</a>
Display LCh instead of Lab</span></font><br>
<font size="-1"><span style="font-family: monospace;"> <a
href="#V">-V</a>
Show running average and std. devation from ref.</span></font><br>
<font size="-1"><span style="font-family: monospace;"> <a
href="#T">-T</a>
Display correlated color temperatures and CRI<br>
</span></font><font size="-1"><span style="font-family:
monospace;"> <a href="#N">-N</a>
Disable auto calibration of instrument</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;"><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>
<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>
<small><span style="font-family: monospace;"> </span><a style="
font-family: monospace;" href="#D">-D [level]</a><span
style="font-family: monospace;">
Print debug diagnostics to stderr</span></small><br>
<font size="-1"><span style="font-family: monospace;"> <a
href="#log"><span style="font-style: italic;">logfile</span></a>
Optional file to save reading results<br style="font-family:
monospace;">
</span></font><small><span style="font-family: monospace;"></span><span
style="font-family: monospace;"></span></small><br>
<h3>Usage Details and Discussion</h3>
<b>spotread</b> operates in a similar fashion to <a
href="chartread.html"> chartread</a>, but allows the reading of a
succession of single color values. This can be useful in diagnosing
issues with profile creation and operation.<br>
<br>
<a name="v"></a>The <b>-v</b> flag causes extra information to be
printed out during chartread operation.<br>
<br>
<a name="s"></a>The <b>-s</b> flag enables the printing out
spectral reflectance/transmittance values, if the instrument
supports this.<br>
<br>
<a name="S"></a>The <b>-S</b> flag enables the plotting of the
spectral reflectance/transmittance values, if the instrument
supports this. If a reference is taken, this will be plotted in red.
You must strike a key in the plot window to continue with another
measurement.<br>
<br>
<a name="c"></a> The instrument is assumed to communicate through a
USB or serial communication port, and the port can be selected with
the <b>-c</b> option, if the instrument is not connected to the
first port. If you invoke <span style="font-weight: bold;">spotread</span>
so as to display the usage information (i.e. "spotread -?" or
"spotread --"), then the discovered USB and serial ports will be
listed. On UNIX/Linux, a list of all possible serial ports are
shown, but not all of them may actually be present on your system.<br>
<br>
<a name="t"></a>If using an Xrite DTP41T or SpectroScanT, and
printing onto transparent or back lit media, use the <b>-t</b> flag
to operate the instrument in transparency mode. If using the
Spectroscan, 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.<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. Values returned are absolute.<br>
<br>
<a name="db"></a>The <span style="font-weight: bold;">-db</span>
flag allows measuring in display mode using instruments that support
this mode, with the brightness normalized to the white value read as
the first reading. 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">spotread</a>.<br>
<br>
<a name="dw"></a>The <span style="font-weight: bold;">-dw</span>
flag allows measuring in display mode using instruments that support
this mode, with the white normalized to the white value read as the
first reading.<br>
<br>
<a name="p"></a>The <span style="font-weight: bold;">-p</span> flag
allows measuring in projector mode, using instruments that support
this mode. Values returned are absolute.<br>
<br>
<a name="pb"></a>The <span style="font-weight: bold;">-pb</span>
flag allows measuring in projector mode using instruments that
support this mode, with the brightness normalized to the white value
read as the first reading. 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">spotread</a>.<br>
<br>
<a name="pw"></a>The <span style="font-weight: bold;">-pw</span>
flag allows measuring in projector mode using instruments that
support this mode, with the white normalized to the white value read
as the first reading.<br>
<br>
<a name="e"></a>The <span style="font-weight: bold;">-e</span> flag
allows measuring in emission mode (e.g. displays or illuminants)
using instruments that support this mode. An adaptive integration
time will be used in devices that support it. Values returned are
absolute.<br>
<br>
<a name="a"></a>The <span style="font-weight: bold;">-a</span> flag
allows measuring in ambient illumination mode using instruments that
support this mode (i.e. Eye-One Display 2). Values returned are
absolute, and include the various color temperatures and Color
Rendering Index (see <span style="font-weight: bold;">-T</span>).
If the instrument does not support ambient mode, emissive mode will
be used instead. An adaptive integration time will be used in
devices that support it. <br>
<br>
<a name="f"></a>The <span style="font-weight: bold;">-f</span> flag
allows measuring a flash with those instruments that support
scanning emissive measurements. The instrument needs to be triggered
by holding down its button, triggering the flash, then releasing the
button, similar to how a reflective strip is read.<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="i"></a>The <b>-i</b> flag allows specifying a standard or
custom illumination spectrum, applied to <span
style="text-decoration: underline;">reflective</span> spectral
data to compute CIE tristimulus values. <b>A</b>, <b>D50</b>, <b>D65</b>,
<b>F5</b>, <b>F8</b>, <b>F10</b> are a selection of standard
illuminant spectrums, with <b>D50</b> being the default. If a
filename is specified instead, it will be assumed to be an Argyll
specific <a href="File_Formats.html#.sp">.sp</a> spectrum file.<br>
<br>
<a name="Q"></a> The <b>-Q</b> flag allows specifying a tristimulus
observer, and is used to compute PCS (Profile Connection Space)
tristimulus values. This is possible for a spectral instrument, or a
colorimeter that has CCSS 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="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="E"></a>The <b>-E</b> option allows the setting of an extra
filter compensation file, that allows for the filtration of the
spectral readings through a medium of some kind, when in emission
mode. This is useful in allowing for such things as telescopic
adapters that use a glass of acrylic lens in the optical path. [<span
style="font-weight: bold;">Note</span> that this is currently only
supported by the Spectrolino driver.]<br>
<br>
<a name="x"></a>The <b>-x</b> option causes the reading to be
displayed as XYZ and Yxy values, rather than the default XYZ and
L*a*b*<br>
<br>
<a name="h"></a>The <b>-h</b> option causes the reading to be
displayed as XYZ and LCh values, rather than the default XYZ and
L*a*b*<br>
<br>
<a name="V"></a>The <b>-V</b> enables average and standard
deviation statistics on the L*a*b* values. This start and is reset
whenever a reference is taken ('r' key). This is useful in
quantifying repeatability.<br>
<br>
<a name="T"></a>The <b>-T</b> option causes various color
temperatures to be displayed, plus the Color Rendering Index. Three
color temperatures will be shown. The first is the classic
Correlated Color Temperature, which is the black body (Plankian)
color closest to the measured color in the CIE 1960 UCS color space.
The second is the black body (Plankian) color that has a minimum
CIEDE2000 error to the measured color. The last is the daylight
color that has a minimum CIEDE2000 error to the measured color. The
delta E between the closest temperature and the measured color is
also shown for each. The Color Rendering Index (CRI Ra) is also
computed if the instrument is capable of spectral measurement. If
the notation <span style="font-weight: bold;">(Invalid)</span> is
displayed after the CRI, then this means that the the spectrum white
point is to far from the black body and Daylight locus to be
meaningful.<br>
<br>
<a name="N"></a>The <b>-N</b> option disables the automatic
calibration of an instrument if it is possible to do so. Sometimes
it is awkward to have to re-calibrate and instrument every time a
tool starts, and unnecessary if the instrument has recently been
calibration, and this switch prevents it happening.<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="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="log"></a>The <span style="font-weight: bold; font-style:
italic;">logfile</span> is an optional file that can be specified
to capture each reading taken. There will be column headers printed
to the first row, and then each reading will be on a separate line
with tab separators.<br>
<br>
All instruments will be used in a spot mode. For the SpectroScan
instrument, the samples can be placed on the table, and the
measuring head positioned before taking a measurement. Note that the
default mode (reflectance measurement) may not be supported by the
instrument, so a mode it does support will be selected
automatically. Override this on the command line if desired. Note
that the DTP51, DTP92, DTP94 and Eye-One Display are colorimeters,
and cannot read spectral information, and that the DTP92 can only
read CRT type displays.<br>
<br>
<hr style="width: 100%; height: 2px;"><br>
Once <b>spotread</b> has established communications with the
instrument, it awaits a command from the user, indicated by the user
hitting a key or activating the instrument switch. XYZ values are in
the range 0 .. 100 for reflective or transmissive readings, and
absolute cd/m^2 for display, emissive and ambient readings.<br>
<br>
The L*a*b* values are computed relative to a D50 100 scale white
point. (Note that using display white relative mode makes the L*a*b
relative to the display white point.)<br>
<br>
If Fluorescent Whiter Additive (FWA) compensated readings are to be
made, then this needs to be enabled with the correct command line
switches, and then setup for each paper white background color, to
establish an FWA reference. There is one FWA reference locations
available for each alphabetic character not used for a special
function (ie. not <span style="font-weight: bold;">H, K, N, Q, R,
S)</span>, keyed to the capital letters <b>A-</b><b>Z</b>,
allowing FWA corrected comparisons between many different media.<br>
<br>
Once a particular reference location is initialized with the FWA
paper color, subsequent readings triggered by using the
corresponding lower case letter <span style="font-weight: bold;">a-z</span>
will use FWA compensation for that keyed location. Note that
readings that are triggered some other way (ie. using a non
alphabetic key, or using the instrument switch) will not be FWA
corrected readings.<br>
<br>
If a non-FWA readings is to be performed, then a reading for a
location that has not been initialised for paper white should be
used, or a non alphabetic key (such as space or return) or
instrument switch trigger should be used.<br>
<br>
If the instrument supports a high resolution spectral mode, then it
can be toggled on and off using the <span style="font-weight:
bold;">h</span> key.<br>
<br>
If the instrument supports stored readings (ie. DTP20), then these
can be ignored using the <span style="font-weight: bold;">n</span>
key.<br>
<br>
The previous reading can be stored as a reference, and delta E's
computed for each reading, using the <b>r</b> key.<br>
<br>
A previous spectral reading can be saved in a spectrum CGATS file
(spectrum.sp) using the <span style="font-weight: bold;">s</span>
key, making this a convenient way of creating a custom illuminant
spectrum.<br>
<br>
A calibration can be initiated using the <span style="font-weight:
bold;">k</span> key.<br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
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