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+<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
+<html>
+ <head>
+ <title>dispcal</title>
+ <meta http-equiv="content-type" content="text/html;
+ charset=ISO-8859-1">
+ <meta name="author" content="Graeme Gill">
+ </head>
+ <body>
+ <h2><b>spectro/dispcal</b></h2>
+ <h3>Summary</h3>
+ Given calibration target information [white point, maximum
+ brightness, and response curve ("gamma")], display a series of test
+ patches on the display, and using the colorimetric values read,
+ create a calibration lookup tables that make the display meet the
+ desired target. The type of instrument is determined by the
+ communication port selected. Emission and display measurement
+ instruments are supported.<br>
+ <h3>Usage</h3>
+ <font size="-1"><span style="font-family: monospace;">dispcal
+ [-options]</span><i style="font-family: monospace;"> inoutfile</i><br
+ style="font-family: monospace;">
+ <span style="font-family: monospace;">&nbsp;</span><a
+ style="font-family: monospace;" href="#v">-v [n]</a><span
+ style="font-family: monospace;">
+ &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ Verbose mode<br>
+ </span></font><font size="-1"><span style="font-family:
+ monospace;">&nbsp;</span><a style="font-family: monospace;"
+ href="#display">-display displayname</a><span
+ style="font-family: monospace;"> [X11 only] Choose X11 display
+ name<br>
+ </span></font><font size="-1"><span style="font-family:
+ monospace;">&nbsp;<a href="#dnm">-d n[,m]</a>
+ &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+ [X11 only]Choose the display from the following list (default
+ 1),<br>
+ &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+and
+optionally
+choose
+a
+different
+display
+m
+for
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ VideoLUT access.</span></font><br>
+ <font size="-1"><span style="font-family: monospace;">&nbsp;<a
+ href="#d">-d n</a>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+Choose
+the
+display
+from
+the
+following
+list
+(default
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ 1)</span></font><br>
+ <span style="font-family: monospace;">&nbsp;<a href="#dweb">-dweb[:port]</a>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ Display via a web server at port (default 8080)</span><br
+ style="font-family: monospace;">
+ <font size="-1"><span style="font-family: monospace;"></span><span
+ style="font-family: monospace;"></span><span style="font-family:
+ monospace;"></span>&nbsp; <span style="font-family: monospace;"></span></font><small
+ 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;"> &nbsp; &nbsp;
+ &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Set communication port from
+ the following list (default 1)<br>
+ </span></small><font size="-1"><span style="font-family:
+ monospace;">&nbsp;</span><a style="font-family: monospace;"
+ href="#r">-r</a><span style="font-family: monospace;">
+ &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+ &nbsp;&nbsp;&nbsp;&nbsp; Report on the calibrated display then
+ exit</span></font><font size="-1"><span style="font-family:
+ monospace;"></span><span style="font-family: monospace;"></span><span
+ style="font-family: monospace;"></span><span style="font-family:
+ monospace;"><br>
+ </span></font><font size="-1"><span style="font-family:
+ monospace;">&nbsp;</span><a style="font-family: monospace;"
+ href="#R">-R</a><span style="font-family: monospace;">
+ &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+ &nbsp;&nbsp;&nbsp;&nbsp; Report on the uncalibrated display then
+ exit</span></font><font size="-1"><span style="font-family:
+ monospace;"></span></font><br>
+ <font size="-1"><span style="font-family: monospace;">&nbsp;</span><a
+ style="font-family: monospace;" href="#m">-m</a><span
+ style="font-family: monospace;">
+ &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+ &nbsp;&nbsp;&nbsp;&nbsp; </span></font><font size="-1"><span
+ style="font-family: monospace;">Skip</span><span
+ style="font-family: monospace;"> adjustment of the monitor
+ controls</span></font><br>
+ &nbsp; <font size="-1"><span style="font-family: monospace;"><a
+ href="#o">-o [profile.icm]</a>&nbsp;&nbsp;&nbsp;&nbsp; Create
+ fast matrix/shaper profile [different filename to outfile.icm]<br>
+ &nbsp;<a href="#O">-O description</a>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ Fast ICC Profile Description string (Default "outfile")<br>
+ &nbsp;<a href="#u">-u</a>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+Update
+previous
+calibration
+and
+(if
+-o
+used)
+ICC
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ profile VideoLUTs</span><span style="font-family: monospace;"></span><span
+ style="font-family: monospace;"></span><br style="font-family:
+ monospace;">
+ <span style="font-family: monospace;">&nbsp;</span><a
+ style="font-family: monospace;" href="#q">-q [lmh]</a><span
+ style="font-family: monospace;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ Quality - Low, Medium (def), High<br>
+ &nbsp;<a href="#p">-p</a>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+
+
+
+
+
+
+
+
+ Use telephoto mode (ie. for a projector) (if available)<br>
+ &nbsp;</span></font><font size="-1"><span style="font-family:
+ monospace;"><a href="#y">-y X</a>
+ &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ Display type - instrument specific list to choose from.</span></font><font
+ size="-1"><span style="font-family: monospace;"><br
+ style="font-family: monospace;">
+ </span><span style="font-family: monospace;">&nbsp;</span><a
+ style="font-family: monospace;" href="#t">-t [temp]</a><span
+ style="font-family: monospace;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+White
+Daylight
+locus
+target,
+optional
+target
+temperaturee
+in
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ deg. K (deflt.)<br>
+ </span></font><font size="-1"><span style="font-family:
+ monospace;">&nbsp;</span><a style="font-family: monospace;"
+ href="#T">-T [temp]</a><span style="font-family: monospace;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+White
+Black
+Body
+locus
+target,
+optional
+target
+temperaturee
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ in deg. K</span></font><br style="font-family: monospace;">
+ <font size="-1"><span style="font-family: monospace;"></span><span
+ style="font-family: monospace;">&nbsp;</span><a
+ style="font-family: monospace;" href="#w">-w x,y</a><span
+ style="font-family: monospace;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ Set the target white point as chromaticity coordinates</span><br
+ style="font-family: monospace;">
+ <span style="font-family: monospace;">&nbsp;</span><a
+ style="font-family: monospace;" href="#b">-b bright</a><span
+ style="font-family: monospace;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ Set the target white brightness in cd/m^2</span><br
+ style="font-family: monospace;">
+ <span style="font-family: monospace;">&nbsp;</span><a
+ style="font-family: monospace;" href="#g">-g gamma</a><span
+ style="font-family: monospace;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ Set the target response curve gamma (Def. 2.4)</span><br
+ style="font-family: monospace;">
+ <span style="font-family: monospace;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ Use "-gl" for L*a*b* curve</span><br style="font-family:
+ monospace;">
+ <span style="font-family: monospace;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ &nbsp; &nbsp;&nbsp;&nbsp;&nbsp; Use "-gs" for sRGB curve<br>
+ &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+Use
+"-g709"
+for
+REC
+709
+curve
+(should
+use
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ -a as well!)<br>
+ &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ Use "-g240" for SMPTE 240M curve </span></font><font size="-1"><span
+ style="font-family: monospace;">(should use -a as well!)</span></font><br>
+ <font size="-1"><span style="font-family: monospace;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ Use "-G2.4 -f0" for BT.1886</span></font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+
+
+
+
+
+
+
+
+
+
+
+
+ <br>
+ <font size="-1"><span style="font-family: monospace;">&nbsp;</span><a
+ style="font-family: monospace;" href="#G">-G gamma</a><span
+ style="font-family: monospace;">
+ &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+ Set the target response curve actual technical gamma<br>
+ &nbsp;<a href="#f">-f [degree]</a>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+Amount
+of
+black
+level
+accounted
+for
+with
+output
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ offset (default all output offset)<br>
+ &nbsp;<a href="#a">-a ambient</a>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ Use viewing condition adjustment for ambient in Lux<br>
+ </span></font><font size="-1"><span style="font-family:
+ monospace;">&nbsp;<a href="#k">-k factor</a>
+ &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+ Amount to try and correct black point hue. Default 1.0, LCD
+ default 0.0<br>
+ </span></font><font size="-1"><span style="font-family:
+ monospace;">&nbsp;<a href="#A">-A rate</a>
+ &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+ Rate of blending from neutral to black point. Default 4.0</span></font><br>
+ <font size="-1"><span style="font-family: monospace;">&nbsp;</span><a
+ style="font-family: monospace;" href="#B">-B bkbright</a><span
+ style="font-family: monospace;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ Set the target black brightness in cd/m^2</span></font><br
+ style="font-family: monospace;">
+ <font size="-1"><span style="font-family: monospace;"></span><span
+ style="font-family: monospace;">&nbsp;</span><a
+ style="font-family: monospace;" href="#e">-e [n]</a><span
+ style="font-family: monospace;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ Run n verify passes on final curves<br>
+ </span></font><font size="-1"><span style="font-family:
+ monospace;">&nbsp;</span><a style="font-family: monospace;"
+ href="#E">-E</a><span style="font-family: monospace;">
+ &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ Run only verify pass on installed calibration curves</span></font><br
+ style="font-family: monospace;">
+ <font size="-1"><span style="font-family: monospace;"></span><span
+ style="font-family: monospace;">&nbsp;<a href="#P">-P
+ ho,vo,ss[,vs]</a>&nbsp;&nbsp;&nbsp;&nbsp; Position test window
+ and scale it</span><br style="font-family: monospace;">
+ <span style="font-family: monospace;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+ho,vi:
+0.0
+=
+left/top,
+0.5
+=
+center,
+1.0
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ = right/bottom etc.</span><br style="font-family: monospace;">
+ <span style="font-family: monospace;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+ss:
+0.5
+=
+half,
+1.0
+=
+normal,
+2.0
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ = double etc.<br>
+ </span></font><font size="-1"><span style="font-family:
+ monospace;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+
+
+
+
+
+
+ ss,vs: = optional horizontal, vertical scale.</span></font><br>
+ <font size="-1"><span style="font-family: monospace;"> &nbsp;<a
+ href="#F">-F</a>
+ &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ Fill whole screen with black background</span></font><font
+ size="-1"><span style="font-family: monospace;"></span></font><br
+ style="font-family: monospace;">
+ <font size="-1"><span style="font-family: monospace;"></span><span
+ style="font-family: monospace;">&nbsp;</span><a
+ style="font-family: monospace;" href="#n">-n</a><span
+ style="font-family: monospace;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+&nbsp;&nbsp;&nbsp;&nbsp;
+[X11
+only]
+Don't
+set
+override
+redirect
+on
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ test window<br>
+ </span></font><font size="-1"><span style="font-family:
+ monospace;">&nbsp;</span><a style="font-family: monospace;"
+ href="#J">-J</a><span style="font-family: monospace;">
+ &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+ &nbsp;&nbsp;&nbsp;&nbsp; Run instrument calibration first<br>
+ </span></font><font size="-1"><span style="font-family:
+ monospace;">&nbsp;<a href="#N">-N</a>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ Disable initial calibration of instrument if possible</span></font><br>
+ <font size="-1"><span style="font-family: monospace;">&nbsp;</span><a
+ style="font-family: monospace;" href="#H">-H</a><span
+ style="font-family: monospace;">
+ &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+ &nbsp;&nbsp;&nbsp;&nbsp; Use high resolution spectrum mode (if
+ available)<br>
+ </span></font><font size="-1"><span style="font-family:
+ monospace;"></span><span style="font-family: monospace;"><br>
+ &nbsp;</span></font><font size="-1"><span style="font-family:
+ monospace;"><span style="text-decoration: underline;"></span><a
+ href="#X1">-X file.ccmx</a>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ Apply Colorimeter Correction Matrix</span></font><br>
+ <span style="font-family: monospace;">&nbsp;<a href="#X2">-X
+ file.ccss</a>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+Use
+Colorimeter
+Calibration
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ Spectral Samples for calibration</span><font size="-1"><span
+ style="font-family: monospace;"><br>
+ </span></font><small><span style="font-family: monospace;">&nbsp;</span><a
+ style="font-family: monospace;" href="#Q">-Q <i>observ</i></a><span
+ style="font-family: monospace;">&nbsp; &nbsp; &nbsp; &nbsp;
+ &nbsp;&nbsp;&nbsp; Choose CIE Observer for spectrometer or CCSS
+ colorimeter data:</span><br style="font-family: monospace;">
+ <span style="font-family: monospace;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 1931_2 </span></small><small><span
+ style="font-family: monospace;">(def.)</span></small><small><span
+ style="font-family: monospace;">, 1964_10, S&amp;B 1955_2, shaw,
+ J&amp;V 1978_2, 1964_10c<br>
+ &nbsp;<a href="#I">-I b|w</a>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ Drift compensation, Black: -Ib, White: -Iw, Both: -Ibw<br>
+ </span></small><font size="-1"><span style="font-family:
+ monospace;">&nbsp;</span><a style=" font-family: monospace;"
+ href="#YA">-<font size="-1">Y</font> A</a><span
+ style="font-family: monospace;">
+ &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+ &nbsp;&nbsp;&nbsp; Use non-adaptive integration time mode (if
+ available).</span></font><br>
+ <small><span style="font-family: monospace;"> </span></small><font
+ size="-1"><span style="font-family: monospace;">&nbsp;</span><a
+ style="font-family: monospace;" href="#C">-C "command"</a><span
+ style="font-family: monospace;">
+ &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Invoke shell
+ "command" each time a color is set</span></font><br>
+ <font size="-1"><span style="font-family: monospace;">&nbsp;</span><a
+ style="font-family: monospace;" href="#M">-M "command"</a><span
+ style="font-family: monospace;">
+ &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Invoke shell
+ "command" each time a color is measured</span></font><font
+ size="-1"><span style="font-family: monospace;"></span><span
+ style="font-family: monospace;"></span></font><br>
+ <font size="-1"><span style="font-family: monospace;">&nbsp;<a
+ href="#W">-W n|h|x</a>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+Override
+serial
+port
+flow
+control:
+n
+=
+none,
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ h = HW, x = Xon/Xoff</span></font><font size="-1"><span
+ style="font-family: monospace;"></span></font><br>
+ <font size="-1"><span style="font-family: monospace;"> </span></font><font
+ size="-1"><span style="font-family: monospace;">&nbsp;</span><a
+ style="font-family: monospace;" href="#D">-D [level]</a><span
+ style="font-family: monospace;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ Print debug diagnostics to stderr</span></font><br
+ style="font-family: monospace;">
+ <font size="-1"><span style="font-family: monospace;"></span><span
+ style="font-family: monospace;">&nbsp;</span><a
+ style="font-family: monospace;" href="#p1"><i>inoutfile</i></a><span
+ style="font-family: monospace;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ </span><span style="font-family: monospace;">Base name for created
+ or updated </span></font><font size="-1"><a style="font-family:
+ monospace;" href="cal_format.html">.cal</a><span
+ style="font-family: monospace;"></span></font><font size="-1"><span
+ style="font-family: monospace;">&nbsp; and <a
+ href="File_Formats.html#ICC">.icm</a> output files</span></font><br>
+ <br>
+ <h3>Comments<br>
+ </h3>
+ This is the tool is used for adjusting and calibrating a display to
+ reach specified target behaviour, and optionally profiling it.&nbsp;
+ For best results on a CRT, you should run this against a neutral
+ grey desktop background, and avoid having any bright images or
+ windows on the screen at the time you run dispcal. You could also
+ use the <span style="font-weight: bold;">-B</span> option to black
+ the whole screen out, although this will make it impossible to
+ control dispcal unless you have more than one display.<br>
+ <br>
+ <a name="v"></a> The <b>-v</b> flag reports progress information,
+ as well as other statistics about the progress of calibration. A
+ numerical argument greater than 1 gives greater verbosity.<br>
+ <br>
+ <a name="display"></a>When running on a UNIX based system that used
+ the X11 Windowing System, <b>dispcal</b> will by default use the
+ $DISPLAY environment variable to determine which local or remote
+ display and screen to read from. This can be overridden by supplying
+ an X11 display name to the <span style="font-weight: bold;">-display</span>
+ option. Note that if Xinerama is active, you can't select the screen
+ using $DISPLAY or -display, you have to select it using the <span
+ style="font-weight: bold;">-d</span> parameter.<br>
+ <br>
+ <a name="d"></a> By default the main display will be the location of
+ the test window. If the system has more than one display or screen,
+ an alternate display/screen can be selected with the <span
+ style="font-weight: bold;">-d</span> parameter. If you invoke <span
+ style="font-weight: bold;">dispcal</span> so as to display the
+ usage information (i.e. "dispcal -?" or "dispcal --"), then the
+ discovered displays/screens will be listed. Multiple displays may
+ not be listed, if they appear as a single display to the operating
+ system (ie. the multi-display support is hidden in the video card
+ driver). On UNIX based system that used the X11 Windowing System,
+ the <span style="font-weight: bold;">-d</span> parameter will
+ override the screen specified by the $DISPLAY or parameter.<br>
+ <br>
+ <span style="font-weight: bold;">Note</span> that if VideoLUTs for a
+ display are not accessible (i.e. no hardware calibration
+ capability), <span style="font-weight: bold;">dispcal</span> will
+ will issue a warning, but continue creating a calibration based on
+ the display "as-is" rather than its native response. See the <a
+ href="dispcal.html#o">-o</a> flag for an explanation of the
+ implications of having no access to the VideoLUTs.<br>
+ <br>
+ On X11 the inability to access VideoLUTs could be because you are
+ trying to access a remote display, and the remote display doesn't
+ support the XF86VidMode extension, or perhaps you are running
+ multiple monitors using NVidia TwinView, or MergedFB, and trying to
+ access anything other than the primary monitor. TwinView and
+ MergedFB don't properly support the XF86VidMode extension for
+ multiple displays. You can use <a href="dispwin.html#r">dispwin -r</a>
+ to test whether the VideoLUTs are accessible for a particular
+ display. See also below, on how to select a different display for
+ VideoLUT access. Also note that dispcal will fail if the Visual
+ depth doesn't match the VideoLUT depth. Typically the VideoLUTs have
+ 256 entries per color component, so the Visual generally needs to be
+ 24 bits, 8 bits per color component.<br>
+ <br>
+ <a name="dnm"></a>Because of the difficulty cause by TwinView and
+ MergedFB in X11 based systems, you can optionally specify a separate
+ display number after the display that is going to be used to present
+ test patches, for accessing the VideoLUT hardware. This must be
+ specified as a single string, e.g. <span style="font-weight: bold;">-d
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ 1,2</span> . Some experimentation may be needed using <a
+ href="dispwin.html">dispwin</a> on such systems, to discover what
+ screen has access to the VideoLUT hardware, and which screens the
+ test patches appear on. You may be able to calibrate one screen, and
+ then share the calibration with another screen. Profiling can be
+ done independently to calibration on each screen.<br>
+ <br>
+ <a name="dweb"></a><span style="font-weight: bold;">-dweb</span> or
+ <span style="font-weight: bold;">-dweb:port</span> starts a
+ standalone web server on your machine, which then allows a local or
+ remote web browser to display the the color test patches. By default
+ port <span style="font-weight: bold;">8080</span> is used, but this
+ can be overridden by appending a <span style="font-weight: bold;">:</span>
+ and the port number i.e. <span style="font-weight: bold;">-dweb:8001</span>.
+ The URL will be <span style="font-weight: bold;">http://</span>
+ then name of the machine or its I.P. address followed by a colon and
+ the port number - e.g something like <span style="font-weight:
+ bold;">http://192.168.0.1:8080</span>. If you use the verbose
+ option (<span style="font-weight: bold;">-v</span>) then a likely
+ URL will be printed once the server is started, or you could run <span
+ style="font-weight: bold;">ipconfig</span> (MSWin) or <span
+ style="font-weight: bold;">/sbin/ifconfig</span> (Linux or OS X)
+ and identify an internet address for your machine that way. <b>JavaScript</b>
+ needs to be enabled in your web browser for this to work.<br>
+ <br>
+ Note that if you use this method of displaying test patches, that
+ there is no access to the display VideoLUTs and that the colors will
+ be displayed with 8 bit per component precision, and any
+ screen-saver or power-saver will not be disabled. You will also be
+ at the mercy of any color management applied by the web browser, and
+ may have to carefully review and configure such color management.
+ See the <a href="#o">-o</a> flag for an explanation of the
+ implications of having no access to the VideoLUTs.<br>
+ <br>
+ <a name="c"></a> <span style="font-weight: bold;">-c</span> 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;">dispcal</span> so as to
+ display the usage information (i.e. "dispcal -?" or "dispcal --"),
+ 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="r"></a> The -<span style="font-weight: bold;">r</span> and
+ <span style="font-weight: bold;"><a name="R"></a>-R </span>flags
+ perform a quick measurement of current display behaviour, reports
+ and then exits. If the <span style="font-weight: bold;">-r</span>
+ flag is used the measurement are taken using the currently loaded
+ calibration (Video LUT) curves. If <span style="font-weight: bold;">-R</span>
+ is use, then the uncalibrated ("raw" or "native") behaviour is
+ measured. Reported are: <br>
+ <br>
+ &nbsp;&nbsp;&nbsp; Black Brightness in cd/m^2<br>
+ &nbsp;&nbsp;&nbsp; White Brightness in cd/m^2<br>
+ &nbsp;&nbsp;&nbsp; The approximate Gamma<br>
+ &nbsp;&nbsp;&nbsp; The white point x,y chromaticity co-ordinates<br>
+ &nbsp;&nbsp;&nbsp; The correlated color temperature in Kelvin, and
+ the CIEDE200 to the Black Body locus.<br>
+ &nbsp;&nbsp;&nbsp; The correlated Daylight temperature in Kelvin,
+ and the CIEDE200 to the Daylight locus.<br>
+ &nbsp;&nbsp;&nbsp; The visual color temperature in Kelvin, and the
+ CIEDE200 to the Black Body locus.<br>
+ &nbsp;&nbsp;&nbsp; The visual Daylight temperature in Kelvin, and
+ the CIEDE200 to the Daylight locus.<br>
+ &nbsp;&nbsp;&nbsp; The visual color temperature in Kelvin<br>
+ (for <span style="font-weight: bold;">-R </span>"raw":)<br>
+ &nbsp;&nbsp;&nbsp; The apparent VideoLUT entry number of significant
+ bits.<br>
+ <br>
+ Note that the correlated color temperature is the temperature of a
+ black body radiator that has the closest color to the white point
+ measured using the traditional CIE 1960 UCS space color difference
+ formula. The correlated daylight temperature is a similar thing,
+ except the CIE daylight locus is used. The visual color temperature
+ values are calculated similarly to the correlated color
+ temperatures, but using the modern CIEDE2000 color difference
+ formula to calculate a better visual approximation to the closest
+ temperature to the displays white point. There will be no difference
+ between the UCS and CIEDE2000 temperatures if the display white
+ point actually lies on the particular locus.<br>
+ <br>
+ <a name="m"></a> The -<span style="font-weight: bold;">m</span>
+ option skips the usual process of adjusting the display monitor
+ contrast, brightness and white point controls, and skips straight to
+ calibration.<br>
+ <br>
+ <a name="o"></a><span style="font-weight: bold;">-o [</span><span
+ style="font-style: italic;">profile.icm</span><span
+ style="font-weight: bold;">]</span> Normally <span
+ style="font-weight: bold;">dispcal</span> creates just a
+ calibration file, which can then be used for subsequent
+ characterization using <a href="dispread.html">dispread</a> and
+ profiling using <a href="colprof.html">colprof</a>. If the <span
+ style="font-weight: bold;">-o</span> flag is used, <span
+ style="font-weight: bold;">dispcal</span> will also create a
+ shaper/matrix profile. By default it will create a profile named <span
+ style="font-weight: bold;">inoutfile.icm</span>, but a differently
+ named file can be created or updated by specifying the name after
+ the <span style="font-weight: bold;">-o</span> flag. If the <span
+ style="font-weight: bold;">-u</span> flag is used with <span
+ style="font-weight: bold;">-o</span>, then the ICC profile <span
+ style="font-weight: bold;">vcgt</span> calibration curves will be
+ updated.<br>
+ <br>
+ Note that if VideoLUT access is not possible for the display, that
+ hardware calibration is not possible. dispcal will create
+ calibration curves anyway with a warning, and if a profile is
+ created, it will not contain a 'vcgt' tag, but instead will have the
+ calibration curves incorporated into the profile itself. If
+ calibration parameters are chosen that change the displays white
+ point or brightness, then this will result in a slightly unusual
+ profile that has a white point that does not correspond with
+ R=G=B=1.0. Some systems may not cope properly with this type of
+ profile. See the <a href="Scenarios.html#PM7">tutorial</a> for a
+ further explanation.<br>
+ <br>
+ <a name="O"></a>The <b>-O</b> parameter allows setting of the
+ shaper/matrix profile description tag. The parameter should be a
+ string that describes the device and profile. With most command line
+ shells, it will be necessary to enclose the parameter with double
+ quotes, so that spaces and other special characters are included in
+ the parameter, and not mistaken for the start of another flag, or as
+ a final command line parameter. Many programs that deal with ICC
+ profiles use the description tag to identify a profile, rather than
+ the profile filename, so using a descriptive string is important in
+ being able to find a profile. By default, the profile file name will
+ be used as the description.<br>
+ <br>
+ <a name="u"></a><span style="font-weight: bold;">-u</span> Normally
+ <span style="font-weight: bold;">dispcal</span> creates a new
+ calibration file and optional profile, based on the requested
+ targets and the response of the display. This can take a fair amount
+ of time, particularly if a high quality level has been selected, so
+ to speed up the process of keeping a display in calibration the <span
+ style="font-weight: bold;">-u</span> flag can be used. This uses
+ the same calibration targets as the previous calibration but does a
+ smaller number of refinement passes, enough to improve the accuracy
+ of the calibration to account for drift in the device. If the <span
+ style="font-weight: bold;">-o</span> flag is used as well, then
+ the ICC profile <span style="font-weight: bold;"></span>will have
+ its vcgt tag updated with the new calibration. This keeps the
+ profile up to date with the display. Normally <span
+ style="font-weight: bold;">dispcal -u</span> will use the same
+ quality level that was specified in the previous calibration, but
+ this can be overridden using the <span style="font-weight: bold;">-q</span>
+ flag. Any options that attempt to change the calibration target (ie.
+ white point, brightness, gamma etc.) will be ignored. Adjustment of
+ the display monitor controls is skipped. A profile cannot be updated
+ if the display does not support hardware calibration (no VideoLUT
+ access).<br>
+ <br>
+ <a name="q"></a>&nbsp; Quality - Low, Medium (def), High. The <span
+ style="font-weight: bold;">-q</span> flag determines how much time
+ and effort to go to in calibrating the display. The higher the
+ quality, the more test readings will be done, the more refinement
+ passes will be done, the tighter will be the accuracy tolerance, and
+ the more detailed will be the calibration of the display. The result
+ will ultimately be limited by the accuracy of the instrument, the
+ repeatability of the display and instrument, and the resolution of
+ the Video Lookup table entries and Digital or Analogue output
+ (RAMDAC).<br>
+ <br>
+ <a name="p"></a>The <span style="font-weight: bold;">-p</span> flag
+ allows measuring in telephoto mode, using instruments that support
+ this mode, e.g. the ColorMunki. Telephoto mode is one for taking
+ emissive measurements from a distance (ie. telespectometer,
+ tele-colorimeter) mode, and typically would be used for measuring
+ projector type displays. If a device does not support a specific
+ telephoto mode, then the normal emissive mode may be suitable for
+ measuring projectors.<br>
+ <br>
+ <a name="y"></a>&nbsp; The <span style="font-weight: bold;">-y</span>
+ flag allows setting the Display Type. 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>. <b>3)</b> Any installed CCSS files
+ (if applicable), or CCMX files. These files are typically created
+ using <a href="file:///D:/src/argyll/doc/ccxxmake.html">ccxxmake</a>,
+ and installed using <a
+ href="file:///D:/src/argyll/doc/oeminst.html">oeminst</a>. The
+ default and Base Calibration types will be indicated in the usage.<br>
+ <br>
+ <a name="t"></a><span style="text-decoration: underline;"></span> <span
+ style="font-weight: bold;">-t</span> Set the target white point
+ locus to the equivalent of a Daylight spectrum of the given
+ temperature in degrees Kelvin. By default the white point target
+ will be the native white of the display, and it's color temperature
+ and delta E to the daylight spectrum locus will be shown during
+ monitor adjustment, and adjustments will be recommended to put the
+ display white point directly on the Daylight locus. If a Daylight
+ color temperature is given as an argument to <span
+ style="font-weight: bold;">-t</span>, then this will become the
+ target of the adjustment, and the recommended adjustments will be
+ those needed to make the monitor white point meet the target.
+ Typical&nbsp; values might be 5000 for matching printed output, or
+ 6500, which gives a brighter, bluer look. A white point temperature
+ different to that native to the display may limit the maximum
+ brightness possible.<br>
+ <br>
+ <a name="T"></a><span style="text-decoration: underline;"></span> <span
+ style="font-weight: bold;">-T</span>&nbsp; Same functionality as
+ the <span style="font-weight: bold;">-t</span> option, except the
+ white point locus will be the Black Body, or Planckian locus, rather
+ than the Daylight locus. While these two white point loci are quite
+ close, they are subtly different. If a temperature is given as an
+ argument, this will become the Black Body target temperature during
+ adjustment.<br>
+ <br>
+ <a name="w"></a><span style="font-weight: bold;">-w</span>&nbsp; An
+ alternative to specifying a&nbsp; white point target in Daylight or
+ Black Body degrees Kevin, is to specify it in chromaticity
+ co-ordinates. This allows the white point to be a color other than
+ one on the Daylight or Black Body. Note that the x,y numbers must be
+ specified as a single string (no space between the numbers and the
+ comma).<br>
+ <br>
+ <a name="b"></a><span style="font-weight: bold;">-b</span>&nbsp; Set
+ the target brightness of white in cd/m^2. If this number cannot be
+ reached, the brightest output possible is chosen, consistent with
+ matching the white point target. Note that many of the instruments
+ are not particularly accurate when assessing the absolute display
+ brightness in cd/m^2. <span style="font-weight: bold;">NOTE</span>
+ that some LCD screens behave a little strangely near their absolute
+ white point, and may therefore exhibit odd behavior at values just
+ below white. It may be advisable in such cases to set a brightness
+ slightly less than the maximum such a display is capable of.<br>
+ <br>
+ <a name="g"></a><span style="font-weight: bold;">-g gamma</span>&nbsp;
+Set
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ the target response curve gamma. This is normally an exponential
+ curve (output = input ^gamma), and defaults to 2.4 on MSWindows and
+ Macintosh OS X 10.6 or latter and Linux/Unix (which is typical of a
+ CRT type displays real response), and 1.8 on a Macintosh (prior to
+ OS X 10.6). Four pre-defined curves can be used as well: the sRGB
+ colorspace response curve, which is an exponent curve with a
+ straight segment at the dark end and an overall response of
+ approximately gamma 2.2 (<span style="font-weight: bold;">-gs</span>),
+the
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ L* curve, which is the response of the CIE L*a*b* perceptual
+ colorspace (<span style="font-weight: bold;">-gl</span>). the REC
+ 709 video standard response curve (<span style="font-weight: bold;">-g709</span>)
+ and the SMPTE 240M video standard response curve (<span
+ style="font-weight: bold;">-g240</span>) <br>
+ <br>
+ <span style="font-weight: bold;">Note</span> that a real display
+ can't reproduce any of these ideal curves, since it will have a
+ non-zero black point, whereas all the ideal curves assume zero light
+ at zero input. In the case of a gamma curve target, dispcal uses an
+ actual technical power curve shape that aims for the same relative
+ output at 50% input as the ideal gamma power curve. To allow for the
+ non-zero black level of a real display, by default <span
+ style="font-weight: bold;">dispcal</span> will offset the target
+ curve values so that zero input gives the actual black level of the
+ display (output offset). This ensures that the target curve better
+ corresponds to the typical natural behavior of displays, but it may
+ not be the most visually even progression from display minimum, but
+ this behavior can be changed using the <span style="font-weight:
+ bold;">-f</span> option (see below).<br>
+ <br>
+ <span style="font-weight: bold;">Also note</span> that many color
+ spaces are encoded with, and labelled as having a gamma of
+ approximately<span style="font-weight: bold;"> 2.2</span> (ie. sRGB,
+ REC 709, SMPTE 240M, Macintosh OS X 10.6), but are actually intended
+ to be displayed on a display with a typical CRT gamma of <span
+ style="font-weight: bold;">2.4</span> viewed in a darkened
+ environment. This is because this <span style="font-weight: bold;">2.2</span>
+ gamma is a source gamma encoding in bright viewing conditions such
+ as a television studio, while typical display viewing conditions are
+ quite dark by comparison, and a contrast expansion of (approx.)
+ gamma 1.1 is desirable to make the images look as intended. So if
+ you are displaying images encoded to the sRGB standard, or
+ displaying video through the calibration, just setting the gamma
+ curve to sRGB or REC 709 (respectively) is probably <span
+ style="font-weight: bold;">not what you want!</span> What you
+ probably want to do, is to set the gamma curve to about gamma 2.4,
+ so that the contrast range is expanded appropriately, or <span
+ style="text-decoration: underline; font-weight: bold;">alternatively</span>
+ use sRGB or REC 709 or a gamm of 2.2 but <span style="font-weight:
+ bold;">also</span> use the <span style="font-weight: bold;">-a</span>
+ parameter to specify the actual ambient viewing conditions, so that
+ <span style="font-weight: bold;">dispcal</span> can make an
+ appropriate contrast enhancement. If your instrument is capable of
+ measuring ambient light levels, then you can do so during the
+ interactive display control adjustment. See
+ &lt;http://www.color.org/sRGB.xalter&gt; for details of how sRGB is
+ intended to be used.<br>
+ <br>
+ It is hard to know whether Apple Macintosh computers prior to OS X
+ 10.6 should also have such an adjustment, since it is not really
+ possible to know whether colors labelled as being in such a
+ colorspace are actually encoded in that gamma with the expectation
+ that they will be displayed on a display with that actual response,
+ or whether they are intended to be displayed on a display that
+ contrast expands by a power 1.1.&nbsp; Both situations might be the
+ case, depending on how source material is created!<br>
+ <br>
+ <a name="G"></a><span style="font-weight: bold;">-G gamma</span>&nbsp;
+As
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ explained above, the gamma value provided to the <span
+ style="font-weight: bold;">-g</span> option is used to set and
+ actual response curve that makes an allowance for the non-zero black
+ of the actual display, and will have the same relative output at 50%
+ input as the ideal gamma power curve, and so best matches typical
+ expectations. The <span style="font-weight: bold;">-G</span> option
+ is an alternative that allows the <span style="font-weight: bold;">actual</span>
+ power to be specified instead, meaning that when combined with the
+ displays non-zero black value, the response at 50% input will
+ probably not match that of the ideal power curve with that gamma
+ value.<br>
+ <br>
+ <a name="f"></a><span style="font-weight: bold;">-f [degree]</span>:
+ As explained in for the <span style="font-weight: bold;">-g</span>
+ and <span style="font-weight: bold;">-G</span> options, real
+ displays do not have a zero black response, while all the target
+ response curves do, so this has to be allowed for in some way. The
+ default way of handling this (equivalent to -f 1.0)&nbsp; is to
+ allow for this at the output of the ideal response curve, by
+ offsetting and scaling the output values.<span style="font-weight:
+ bold;"></span> This defined a curve that will match the responses
+ that many other systems provide and may be a better match to the
+ natural response of the display, but will give a less visually even
+ response from black<span style="font-weight: bold;"></span>. The
+ other alternative is to offset and scale the input values into the
+ ideal response curve so that zero input gives the actual non-zero
+ display response. This ensures the most visually even progression
+ from display minimum, but might be hard to achieve since it is
+ different to the naturally response of a display. A subtlety is to
+ provide a split between how much of the offset is accounted for as
+ input to the ideal response curve, and how much is accounted for at
+ the output, and this can be done by providing a parameter <span
+ style="font-weight: bold;">-f degree</span>, where the degree is
+ 0.0 accounts for it all as input offset, and 1.0 accounts for all of
+ it as output offset. If <span style="font-weight: bold;">-f</span>
+ is used without a specified degree, a degree of 0.0 is assumed, the
+ opposite of the default. <span style="font-weight: bold;">Note</span>
+ that using all input offset (degree == 0.0) is equivalent to the use
+ of the <span style="font-weight: bold;">BT.1886</span> transfer
+ function.<br>
+ <br>
+ <a name="a"></a><span style="font-weight: bold;">-a ambient</span>:
+ As explained for the <span style="font-weight: bold;">-g</span>
+ parameter, often colors are encoded in a situation with viewing
+ conditions that are quite different to the viewing conditions of a
+ typical display, with the expectation that this difference in
+ viewing conditions will be allowed for in the way the display is
+ calibrated. The <span style="font-weight: bold;">-a</span> option
+ is a way of doing this. By default <span style="font-weight: bold;">dispcal</span>
+ will not make any allowances for viewing conditions, but will
+ calibrate to the specified response curve, but if the <span
+ style="font-weight: bold;">-a</span> option is used, or the
+ ambient level is measured during the interactive display controls
+ portion of the calibration, an appropriate viewing conditions
+ adjustment will be performed. For a gamma value or sRGB, the
+ original viewing conditions will be assumed to be that of the sRGB
+ standard viewing conditions, while for REC 709 and SMPTE 240M they
+ will be assumed to be television studio viewing conditions. By
+ specifying or measuring the ambient lighting for your display, a
+ viewing conditions adjustment based on the CIECAM02 color appearance
+ model will be made for the brightness of&nbsp; your display and the
+ contrast it makes with your ambient light levels. <br>
+ <br>
+ <a name="k"></a><span style="font-weight: bold;">-k factor</span>:
+ Normally this will be set automatically, based on the measured black
+ level of the display. A <span style="font-weight: bold;">-k</span>
+ factor of 1.0 will make all colors down the neutral axis (R=G=B)
+ have the same hue as the chosen white point. Near the black point,
+ red, green or blue can only be added, not subtracted from zero, so
+ the process of making the near black colors have the desired hue,
+ will <span style="font-weight: bold;">lighten</span> them to some
+ extent. For a device with a good contrast ratio or a black point
+ that has nearly the same hue as the white, this should not affect
+ the contrast ration too severely. If the device contrast ratio is
+ not so good, and the native black hue is noticeably different to
+ that of the chosen white point (which is often the case for <span
+ style="font-weight: bold;">LCD</span> type displays, or <span
+ style="font-weight: bold;">CRT</span> type displays with one
+ channel which has a poor level of black), this could have a
+ noticeably detrimental effect on an already limited contrast ratio,
+ and result in a black that is not as good as it can be, and a lower
+ <span style="font-weight: bold;">-k</span> factor should be used. <span
+ style="font-weight: bold;">-k</span> values can range between 0.0
+ (no correction of black) to 1.0 (full correction of black). If less
+ than full correction is chosen, then the resulting calibration
+ curves will have the target white point down most of the curve, but
+ will then blend over to the native or compromise black point that is
+ blacker, but not of the right hue. The rate of this blend can be
+ controlled with the <span style="font-weight: bold;">-A</span>
+ parameter (see below).<br>
+ <br>
+ <a name="A"></a><span style="font-weight: bold;">-A rate</span>:&nbsp;
+If
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ the black point is not being set completely to the same hue as the
+ white point (ie. because the <span style="font-weight: bold;">-k</span>
+ factor is less than 1.0), then the resulting calibration curves will
+ have the target white point down most of the curve, but will then
+ blend over to the native or compromise black point that is blacker,
+ but not of the right hue. The rate of this blend can be controlled
+ with the <span style="font-weight: bold;">-A</span> parameter. The
+ default value 4.0, which results in a target that switches from the
+ white point target to the black, moderately close to the black
+ point. While this typically gives a good visual result with the
+ target neutral hue being maintained to the point where the crossover
+ to the black hue is not visible, it may be asking too much of some
+ displays (typically LCD type displays), and there may be some visual
+ effects due to inconsistent color with viewing angle. For this
+ situation a smaller value may give a better visual result (e.g. try
+ values of 3.0 or 2.0. A value of 1.0 will set a pure linear blend
+ from white point to black point). If there is too much coloration
+ near black, try a larger value, e.g. 6.0 or 8.0.<br>
+ <br>
+ <a name="B"></a><span style="font-weight: bold;">-B</span>&nbsp; Set
+ the target brightness of black in cd/m^2. Setting too high a value
+ may give strange results as it interacts with trying to achieve the
+ target "advertised" gamma curve shape. You could try using -f 1 if
+ this causes a problem.<br>
+ <br>
+ <a name="e"></a><span style="font-weight: bold;">-e [n]</span> Run <span
+ style="font-weight: bold;">n</span> verify passes on the final
+ curves. This is an extra set of instrument readings, that can be
+ used to estimate how well the device will match the targets with the
+ computed calibration curves. Note that the usefulness of the
+ verification is sometimes limited by the repeatability of the device
+ &amp; instrument readings. This is often evident for CRT displays,
+ which (due to their refresh rate) flicker. More than one
+ verification pass can be done by providing the parameter <span
+ style="font-weight: bold;">n</span>, and by then comparing the
+ successive verifications, some idea of the repeatability can be
+ ascertained. The verification uses a fixed number of semi-random
+ test values to test the calibration.<br>
+ <br>
+ <a name="E"></a><span style="font-weight: bold;">-E</span> Run
+ verify pass on the display as it is currently setup (currently
+ installed LUT curves). This will use the usual input parameters to
+ establish the expected (target) characteristic. <span
+ style="font-weight: bold;">Note</span> that if the initial
+ calibration was modified due to it being out of gamut of the
+ display, verify will show the resulting discrepancy. You can use <a
+ href="dispwin.html">dispwin</a> to load a <span
+ style="font-weight: bold;">.cal</span> file into the display
+ before running dispcal <span style="font-weight: bold;">-E</span>.
+ Note that if you set an Ambient light level interactively during the
+ calibration, you need to enter the same number that was measured and
+ set using the <span style="font-weight: bold;">-a</span> parameter
+ for verify.<br>
+ <br>
+ <a name="P"></a> The <span style="font-weight: bold;">-P</span>
+ parameter allows you to position and size the test patch window. By
+ default it is places in the center of the screen, and sized
+ appropriately for the type of instrument. The <span
+ style="font-weight: bold;">ho</span> and <span
+ style="font-weight: bold;">vo</span> values govern the horizontal
+ and vertical offset respectively. A value of 0.0 positions the
+ window to the far left or top of the screen, a value of 0.5
+ positions it in the center of the screen (the default), and 1.0
+ positions it to the far right or bottom of the screen. If three
+ parameters are provided, then the <span style="font-weight: bold;">ss</span>
+ parameter is a scale factor for the test window size. A value of 0.5
+ for instance, would produce a half sized window. A value of 2.0 will
+ produce a double size window. If four parameters are provided, then
+ the last two set independent horizontal and vertical scaling
+ factors. Note that the ho,vo,ss or ho,vo,hs,vs numbers must be
+ specified as a single string (no space between the numbers and the
+ comma). For example, to create a double sized test window at the top
+ right of the screen, use <span style="font-weight: bold;">-P 1,0,2</span>
+ . To create a window twice as wide as high: <span
+ style="font-weight: bold;">-P 1,0,2,1</span>.<br>
+ <br>
+ <a name="F"></a> The <span style="font-weight: bold;">-F</span>
+ flag causes the while screen behind the test window to be masked
+ with black. This can aid black accuracy when measuring CRT displays
+ or projectors.<br>
+ <br>
+ <a name="n"></a><span style="font-weight: bold;">-n</span> When
+ running on a UNIX based system that used the X11 Windowing System, <b>dispcal</b>
+ normally selects the override redirect so that the test window will
+ appear above any other windows on the display. On some systems this
+ can interfere with window manager operation, and the <b>-n</b>
+ option turns this behaviour off.<br>
+ <br>
+ <a name="J"></a> The -<span style="font-weight: bold;">J</span>
+ option runs through the black and sensor relative calibration
+ routines for the Xrite DTP92 and DTP94 instruments, the black level
+ calibration for the Eye-One Display 1, and a CRT frequency
+ calibration for the Eye-One Display 2. For the black calibration the
+ instrument should be placed on an opaque, black surface, and any
+ stray light should be avoided by placing something opaque over the
+ instrument. If a Spectrolino is being used, then a white and black
+ calibration will always be performed before the instrument can be
+ placed on the display, unless the <a href="dispcal.html#N">-N</a>
+ flag is used. Generally it is not necessary to do a calibration
+ every time an instrument is used, just now and again. There is also
+ no point in doing&nbsp; a CRT frequency calibration, as this will be
+ done automatically at the commencement of patch reading, and will be
+ lost between runs.<br>
+ <br>
+ <a name="N"></a> <span style="font-weight: bold;">-N</span> Any
+ instrument that requires regular calibration will ask for
+ calibration on initial start-up. 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 initial calibration if a valid and not timed out
+ previous calibration is 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="H"></a> The -<span style="font-weight: bold;">H</span>
+ option turns on high resolution spectral mode, if the instrument
+ supports it, such as the Eye-One Pro. See <a
+ href="instruments.html">Operation of particular instruments</a>
+ for more details. This may give better accuracy for display
+ measurements.<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="Q"></a> The <b>-Q</b> flag allows specifying a tristimulus
+ observer, and is used to compute PCS (Profile Connection Space)
+ tristimulus values from spectral readings or using a colorimeter
+ that has CCSS capability. The following choices are available:<br>
+ <b>&nbsp; 1931_2</b> selects the standard CIE 1931 2 degree
+ observer. The default.<br>
+ &nbsp; <b>1964_10</b> selects the standard CIE 1964 10 degree
+ observer.<br>
+ &nbsp; <b>1955_2</b> selects the Stiles and Birch 1955 2 degree
+ observer<br>
+ &nbsp; <b>1978_2 </b>selects the Judd and Voss 1978 2 degree
+ observer<br>
+ &nbsp; <b>shaw</b> selects the Shaw and Fairchild 1997 2 degree
+ observer<br>
+ &nbsp; <b>1964_10c</b> selects a version of the CIE 1964 10 degree
+ observer that has been adjusted using a 3x3 matrix to better agree
+ with the 1931 2 degree observer.<br>
+ <br>
+ <span style="font-weight: bold;">NOTE</span> that if you select
+ anything other than the default 1931 2 degree observer, that the Y
+ values will not be cd/m^2, due to the Y curve not being the CIE 1924
+ photopic V(&#955;) luminosity function.<br>
+ <br>
+ <a name="I"></a> The -<span style="font-weight: bold;">I <span
+ style="font-style: italic;">b|w</span></span> options invoke
+ instrument black level, and display white level compensation
+ (respectively). Instrument black level drift compensation attempts
+ to combat instrument black calibration drift by using a display
+ black test patch as a reference. If an instrument is not
+ acclimatised sufficiently to the measurement conditions, changes in
+ temperature can affect the black readings. Display white level drift
+ compensation attempts to combat changes in display brightness as it
+ warms up by measuring a white patch every so often, and using it to
+ normalise all the other readings. If just instrument black drift
+ compensation is needed, use <span style="font-weight: bold;">-Ib</span>.
+ If just display white level compensation is needed, use <span
+ style="font-weight: bold;">-Iw</span>. If both are needed, use <span
+ style="font-weight: bold;">-Ibw</span> or <span
+ style="font-weight: bold;">-Iwb</span>.<span style="font-weight:
+ bold;"> </span><br>
+ <br>
+ <a name="YA"></a> The -<span style="font-weight: bold;">Y A</span>
+ option uses a non-adaptive integration time emission measurement
+ mode, if the instrument supports it, such as the Eye-One Pro or
+ ColorMunki. By default an adaptive integration time measurement mode
+ will be used for emission measurements, but some instruments support
+ a fixed integration time mode that can be used with display devices.
+ This may give increased consistency and faster measurement times,
+ but may also give less accurate low level readings.<br>
+ <br>
+ <a name="C"></a> The -<span style="font-weight: bold;">C</span> <span
+ style="font-weight: bold;">"command" </span>option allows a
+ method of relaying each test value to some other display than that
+ on the system running dispcal (for instance, a photo frame, PDA
+ screen etc.), by causing the given command to be invoked to the
+ shell, with six arguments. The first three arguments are the RGB
+ test color as integers in the range 0 to 255, the second three
+ parameters are the RGB test color as floating point numbers in the
+ range 0.0 to 1.0. The script or tool should relay the given color to
+ the screen in some manner (e.g. by generating a raster file of the
+ given color and sending it to the display being profiled), before
+ returning. Note that a test window will also be created on the
+ system running dispread.<br>
+ <br>
+ <a name="M"></a> The -<span style="font-weight: bold;">M</span> <span
+ style="font-weight: bold;">"command" </span>option allows a
+ method of gathering each test value from some external source, such
+ as an instrument that is not directly supported by Argyll. The given
+ command is involked to the shell, with six arguments. The first
+ three arguments are the RGB test color as integers in the range 0 to
+ 255, the second three parameters are the RGB test color as floating
+ point numbers in the range 0.0 to 1.0. The script or tool should
+ create a file called <span style="font-weight: bold;">"command.meas</span>"
+ that contains the XYZ values for the given RGB (or measured from the
+ test window) in cd/m^2 as three numbers separated by spaces, before
+ returning. If the command returns a non-zero return value, dispcal
+ will abort. Note that a test window will also be created on the
+ system running dispcal.<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><span style="font-weight: bold;">inoutfile</span>
+ The final parameter on the command line is the base filename for the
+ <a href="cal_format.html">.cal</a> file and the optional ICC
+ profile. Normally this will be created (or an existing file will be
+ overwritten). If the <span style="font-weight: bold;">-u</span>
+ flag is used, then these files will be updated. If a different ICC
+ profile name needs to be specified, do so as an argument to the <span
+ style="font-weight: bold;">-o</span> flag.<br>
+ <br>
+ <span style="font-weight: bold;">NOTE</span> that on an X11 system,
+ if the environment variable <span style="font-weight: bold;">ARGYLL_IGNORE_XRANDR1_2</span>
+ is set (ie. set it to "yes"), then the presence of the XRandR 1.2
+ extension will be ignored, and other extensions such as Xinerama and
+ XF86VidMode extension will be used. This may be a way to work around
+ buggy XRandR 1.2 implementations.<br>
+ <br>
+ <hr style="width: 100%; height: 2px;">
+ <h2><a name="Adjustment"></a>Discussion and guide to display control
+ adjustment:</h2>
+ <br>
+ The adjustment of the display controls (brightness, contrast, R, G
+ &amp; B channel controls etc.) is very dependent on the particular
+ monitor. Different types and brands of monitors will have different
+ controls, or controls that operate in different ways. Some displays
+ have almost no user controls, and so you may well be best skipping
+ display adjustment, and going straight to calibration.<br>
+ <br>
+ Almost all LCD displays lack a real <span style="font-weight:
+ bold;">contrast</span> control. Those that do present such a
+ control generally fake it by adjusting the video signal. For this
+ reason it is usually best to set an LCD's <span style="font-weight:
+ bold;">contrast</span> control at its neutral setting (ie. the
+ setting at which it doesn't change the video signal). Unfortunately,
+ it can be hard to know what this neutral setting is. On some
+ displays it is 50%, others 75%. If the LCD display has a "reset to
+ factory defaults" mode, then try using this first, as a way of
+ setting the <span style="font-weight: bold;">contrast</span>
+ control to neutral. The LCD <span style="font-weight: bold;">brightness</span>
+ control generally adjusts the level of backlighting the display
+ gets, which affects the maximum brightness, and also tends to raise
+ or lower the black level in proportion, without changing the
+ displays response curve shape or overall contrast ratio. If your LCD
+ display has a <span style="font-weight: bold;">backlight</span>
+ control as well as a <span style="font-weight: bold;">brightness</span>
+ control, then the brightness control is also probably being faked,
+ and you are probably better off setting it to it's neutral setting,
+ and using the <span style="font-weight: bold;">backlight</span>
+ control in place of <span style="font-weight: bold;">brightness</span>
+ in the following adjustments.<br>
+ <br>
+ Some high end displays have the ability to mimic various standard
+ colorspaces such as sRGB or AdobeRGB. You could choose to calibrate
+ and profile the display in such an emulation mode, although you
+ probably don't want to fight the emulations white point and gamma.
+ To get the best out of such a display you really want to choose it's
+ "Native Gamut" setting, whatever that is called. Note that some
+ people have reported bad experiences in trying to use "6-axis custom
+ controls" on displays such as the Dell U2410, so attempting to use
+ such a mode should be approached with caution. Ideally such a mode
+ should be used to give just the underlying native display response,
+ but the settings to achieve this may be very difficult to determine,
+ and/or it may not be possible, depending on how such a mode distorts
+ the RGB signals.<br>
+ <br>
+ On CRT based displays, the <span style="font-weight: bold;">brightness</span>
+ control generally adjusts the black level of the display (sometimes
+ called the <span style="font-weight: bold;">offset</span>), and as
+ a side effect, tends to change the maximum brightness too. A CRT <span
+ style="font-weight: bold;">contrast</span> control generally
+ adjusts the maximum brightness (sometimes called <span
+ style="font-weight: bold;">gain</span>) without affecting the
+ black level a great deal. On a CRT both the <span
+ style="font-weight: bold;">brightness</span> and <span
+ style="font-weight: bold;">contrast</span> controls will tend to
+ affect the shape or gamma of the display response curve.<br>
+ <br>
+ Many displays have some sort of color temperature adjustment. This
+ may be in the form of some pre-set color temperatures, or in the
+ form of individual Red, Green and Blue channel gain adjustments.
+ Some CRT displays also have R, G &amp; B channel offset adjustments
+ that will affect the color temperatures near black, as well as
+ affect the individual channels curve shape. The color temperature
+ adjustment will generally affect the maximum brightness, and may
+ also affect the black level and the shape of the display response
+ curves.<br>
+ <br>
+ Some special (expensive) LCD displays may have a white point
+ adjustment that changes the color of the backlight. If you do not
+ have one of these types of LCD displays, then attempting to change
+ the white point of the display (even if it appears to have a "<span
+ style="font-weight: bold;">white point selection</span>" or <span
+ style="font-weight: bold;">R/G/B</span> "<span style="font-weight:
+ bold;">gain</span>" controls") may not be a good idea, as once
+ again these controls are probably being faked by manipulating the
+ signal levels. Even if you do manage to change the white point
+ significantly, it may do things like change the mid tone color too
+ dramatically, or create a display response that is hard to correct
+ with calibration, or results in side effects such as quantization
+ (banding) or other undesirable effects. You may have to try out
+ various controls (and your aim points for the display calibration),
+ to decide what is reasonable to attempt on an LCD display.<br>
+ <br>
+ Due to the variety of controls as well as the interaction between
+ them, it can be an iterative process to arrive at a good monitor
+ set-up, before proceeding on to calibrating and profiling a display.
+ For this reason, <span style="font-weight: bold;">dispcal</span>
+ offers a menu of adjustment modes, so that the user can
+ interactively and iteratively adjust the display controls to meet
+ the desired targets.<br>
+ <br>
+ &nbsp; 1) Black level (CRT: Brightness)<br>
+ &nbsp; 2) White point (Color temperature, R,G,B, Gain/Contrast)<br>
+ &nbsp; 3) White level (CRT: Gain/Contrast, LCD:
+ Brightness/Backlight)<br>
+ &nbsp; 4) Black point (R,G,B, Offset/Brightness)<br>
+ &nbsp; 5) Check all<br>
+ &nbsp; 6) Measure and set ambient for viewing condition adjustment<br>
+ &nbsp; 7) Continue on to calibration<br>
+ &nbsp; 8) Exit<br>
+ <br>
+ There are four basic adjustment modes. Normally one would proceed
+ through them in the order above, then perhaps repeat the first
+ adjustment, before checking the overall settings. The White point
+ and White level modes operate slightly differently, depending on
+ whether a white target point has been set using the <span
+ style="font-weight: bold;">-t -T</span> or <span
+ style="font-weight: bold;">-w</span> options, and on whether a
+ brightness target has been set using the <span style="font-weight:
+ bold;">-b</span> option.<br>
+ <br>
+ <br>
+ The first mode lets you adjust the black level of a CRT display.
+ Given the current white level, it calculates a value that should
+ produce a 1% display brightness if the black level is set correctly.
+ After doing some initial measurements, it will show the target
+ brightness value (in cd/m^2) on one line, and then underneath it
+ will show continuously updated readings from the display. The left
+ most character will switch from '\' to '/' or back again each time a
+ reading is updated. Some instruments can be quite slow in measuring
+ dark colors, and it's best to wait for a reading update before
+ changing the controls more than once. Underneath the target value is
+ displayed the current reading, and to the right of this is a '+',
+ '-' or '=' symbol, which gives a hint as to which way to adjust the
+ brightness control to improve the match to the target.<br>
+ <br>
+ <small style="font-weight: bold;"><span style="font-family:
+ monospace;">&nbsp; Adjust CRT brightness to get target level.
+ Press space when done.</span><br style="font-family: monospace;">
+ <span style="font-family: monospace;">&nbsp;&nbsp; &nbsp; Target
+ 0.60</span><br style="font-family: monospace;">
+ <span style="font-family: monospace;">&nbsp; / Current 0.68&nbsp;
+ -</span></small><br>
+ <br>
+ Once happy with the adjustment, press space to go back to the menu.<br>
+ <br>
+ <br>
+ The second mode lets you adjust the color of the white point of the
+ display. If a target white point has been set, it will show the
+ target brightness value (in cd/m^2) on one line, together with the
+ target chromaticity co-ordinates for the white point, and then
+ underneath it will show continuously updated readings from the
+ display. The left most character will switch from '\' to '/' or back
+ again each time a reading is updated. Underneath the target
+ brightness value is displayed the current reading, and then the
+ current chromaticity co-ordinate values. To the right of this is the
+ current delta E of the white point from the target, and further to
+ the right are hints '+', '-' or '='&nbsp; as to which direction to
+ adjust the individual Red, Green and Blue gain settings to move the
+ white point in the direction of the target, and reduce the delta E.
+ If the symbol is doubled, then this channel will have the greatest
+ effect. If you do not have individual channel gain controls, then
+ try choosing amongst color temperature pre-sets, to find one with
+ the lowest delta E. Depending on the stability of the display, the
+ coarseness of the controls, and the repeatability of the instrument,
+ you may not be able to get a perfectly zero delta E.<br>
+ <br>
+ &nbsp;&nbsp; <small style="font-weight: bold;"><span
+ style="font-family: monospace;">Adjust R,G &amp; B gain to get
+ target x,y. Press space when done.<br>
+ &nbsp;&nbsp; &nbsp; Target B 60.00, x 0.3451, y 0.3516<br>
+ &nbsp; / Current B 60.05, x 0.3426, y 0.3506&nbsp; DE&nbsp;
+ 1.4&nbsp; R+&nbsp; G+&nbsp; B--</span><span style="font-family:
+ monospace;"></span></small><br>
+ <br>
+ If you did not set a white point target, then the information shown
+ is a little different - it will show the initial white point value,
+ as well as the color temperature, and the CIEDE2000 of the white
+ point to either the Daylight or Black Body locus (depending on
+ whether the <span style="font-weight: bold;">-T</span> flag was
+ set). The constantly updated values show the same thing, and the
+ Red, Green and Blue control hints show the direction to adjust the
+ controls to place the white point on the locus. The control that
+ will have the most direct effect on the color temperature will be
+ the Blue, while the Green will most directly move the white point
+ towards or away from the locus, thereby reducing the delta E of the
+ white point to the locus (but there is interaction).<br>
+ <br>
+ <small style="font-weight: bold;"><span style="font-family:
+ monospace;">Adjust R,G &amp; B gain to desired white point.
+ Press space when done.</span><br style="font-family: monospace;">
+ <span style="font-family: monospace;">&nbsp; Initial B 47.25, x
+ 0.3417, y 0.3456, CDT 5113 DE&nbsp; 6.9</span><br
+ style="font-family: monospace;">
+ <span style="font-family: monospace;">\ Current B 47.38, x 0.3420,
+ y 0.3460&nbsp; CDT 5104 DE&nbsp; 6.7&nbsp; R-- G+&nbsp; B-</span></small><br>
+ <br>
+ &nbsp;The brightness value is just there as a guide to what effect
+ the adjustment is having on the overall brightness. Usually the
+ white level brightness is adjusted using the next adjustment mode.
+ Once happy with the adjustment, press space to go back to the menu.<br>
+ <br>
+ <br>
+ The third mode lets you adjust the brightness of white on the
+ display. If you set a target brightness using the <span
+ style="font-weight: bold;"><span style="font-weight: bold;">-b</span></span>
+ parameter, it will show the target brightness value (in cd/m^2) on
+ one line, and then underneath it will show continuously updated
+ readings from the display. The left most character will switch from
+ '\' to '/' or back again each time a reading is updated. Underneath
+ the target value is displayed the current reading, and to the right
+ of this is a '+', '-' or '=' symbol, which gives a hint as to which
+ way to adjust the CRT contrast or LCD brightness control to improve
+ the match to the target.<br>
+ <br>
+ &nbsp;&nbsp; <small style="font-weight: bold;"><span
+ style="font-family: monospace;">Adjust CRT Contrast or LCD
+ Brightness to get target level. Press space when done.<br>
+ &nbsp;&nbsp; &nbsp; Target 60.00<br>
+ &nbsp; / Current 59.96&nbsp; +</span><span style="font-family:
+ monospace;"></span></small><br>
+ <br>
+ If you did not set a brightness target, it will show the initial
+ brightness as the target, and the current brightness, which you can
+ then set any way you want:<br>
+ <br>
+ <small style="font-weight: bold;"><span style="font-family:
+ monospace;">Adjust CRT Contrast or LCD Brightness to desired
+ level. Press space when done.</span><br style="font-family:
+ monospace;">
+ <span style="font-family: monospace;">&nbsp; Initial 47.32</span><br
+ style="font-family: monospace;">
+ <span style="font-family: monospace;">/ Current 47.54</span></small><br>
+ <br>
+ Once happy with the adjustment, press space to go back to the menu.<br>
+ <br>
+ <br>
+ The fourth mode lets you adjust the color of the black point of the
+ display, if the display has Red, Green and Blue channel offset
+ controls. It will show the target 1% brightness value (in cd/m^2) on
+ one line, together with the target chromaticity co-ordinates for the
+ black point, and then underneath it will show continuously updated
+ readings from the display. The left most character will switch from
+ '\' to '/' or back again each time a reading is updated. Underneath
+ the target brightness value is displayed the current reading, and
+ then the current chromaticity co-ordinate values. To the right of
+ this is the current delta E of the black point from the target, and
+ further to the right are hints '+', '-' or '='&nbsp; as to which
+ direction to adjust the individual Red, Green and Blue offset
+ settings to move the black point in the right direction. If the
+ symbol is doubled, then this channel will have the greatest effect.
+ <br>
+ <br>
+ <span style="font-family: monospace;"><span style="font-weight:
+ bold;">&nbsp; Adjust R,G &amp; B offsets to get target x,y.
+ Press space when done.<br>
+ &nbsp;&nbsp; &nbsp; Target B 0.60, x 0.3451, y 0.3516<br>
+ &nbsp; \ Current B 0.62, x 0.2782, y 0.2331&nbsp; DE&nbsp;
+ 10.3&nbsp; R+&nbsp; G++ B-</span></span><small
+ style="font-weight: bold;"><span style="font-family: monospace;"></span><span
+ style="font-family: monospace;"></span></small><br>
+ <br>
+ The 1%&nbsp; brightness value is just there as a guide to what
+ effect the adjustment is having on the 1% brightness level. The
+ combined channel offsets may have an effect on this in combination
+ with the CRT brightness control. Press space to go back to the menu.<br>
+ <br>
+ <br>
+ The fifth selection checks on the overall settings.&nbsp; If targets
+ have been set, it will be like:<br>
+ <br>
+ <small style="font-weight: bold;"><span style="font-family:
+ monospace;">&nbsp; Target Brightness = 50.00, Current = 47.44,
+ error = -5.1%<br>
+ &nbsp; Target 50% Level&nbsp; = 10.32, Current =&nbsp; 8.10,
+ error = -4.4%<br>
+ &nbsp; Target Near Black =&nbsp; 0.47, Current =&nbsp; 0.68,
+ error =&nbsp; 0.4%<br>
+ &nbsp; Target white = x 0.3458, y 0.3586, Current = x 0.3420, y
+ 0.3454, error =&nbsp; 7.55 DE<br>
+ &nbsp; Target black = x 0.3458, y 0.3586, Current = x 0.2908, y
+ 0.2270, error = 29.69 DE</span><span style="font-family:
+ monospace;"></span></small><br>
+ <br>
+ or if no targets are set:<br>
+ <br>
+ <small style="font-weight: bold;"><span style="font-family:
+ monospace;">&nbsp; Current Brightness = 46.28</span><br
+ style="font-family: monospace;">
+ <span style="font-family: monospace;">&nbsp; Target 50%
+ Level&nbsp; = 10.07, Current =&nbsp; 7.52, error = -5.5%</span><br
+ style="font-family: monospace;">
+ <span style="font-family: monospace;">&nbsp; Target Near Black
+ =&nbsp; 0.46, Current =&nbsp; 0.46, error = -0.0%</span><br
+ style="font-family: monospace;">
+ <span style="font-family: monospace;">&nbsp; Current white = x
+ 0.3439, y 0.3466, VCT 5098K DE&nbsp; 3.0</span><br
+ style="font-family: monospace;">
+ <span style="font-family: monospace;">&nbsp; Target black = x
+ 0.3439, y 0.3466, Current = x 0.3093, y 0.2165, error = 30.30 DE</span></small><br>
+ <br>
+ and will then go back to the menu.<br>
+ <br>
+ The sixth selection <span style="font-weight: bold;">6)</span>
+ allows the reading of you ambient lighting conditions if your
+ instrument supports such a mode. Doing so will enable the <span
+ style="font-weight: bold;">-a</span> option to compensate for your
+ viewing conditions in the subsequent calibration. See <a
+ href="dispcal.html#a">-a</a>.<br>
+ <br>
+ Once&nbsp; you're happy with the display set-up, you can either
+ proceed on to the rest of the calibration by selecting <span
+ style="font-weight: bold;">7)</span>, or exit and re-start by
+ selecting <span style="font-weight: bold;">8)</span>. You might
+ want to re-start if you want to change the calibration targets.<br>
+ <br>
+ <hr style="width: 100%; height: 2px;">
+ <h2>Other caveats:</h2>
+ NOTE that some <span style="font-weight: bold;">LCD</span> screens
+ behave a little strangely near their absolute white point, and may
+ therefore exhibit odd behavior at values just below white. It may be
+ advisable in such cases to set a brightness slightly less than the
+ maximum such a display is capable of.<br>
+ <br>
+ The program attempts to stop any screensaver or powersaver from
+ interfering with the measurements, but this may not be effective on
+ some systems, so it may be necessary to manually disable the
+ screensaver and/or powersaver before commencing the calibration with
+ a large number of patches.<br>
+ <br>
+ The calibration tables produced maintain the maximum level of
+ precision available on a system. If the display has VideoLUTs
+ available (Video Lookup Tables that the frame buffer values pass
+ through on their way to the display) and thier outputs are better
+ than 8 bits per component, then the resulting curves can reflect
+ this, although few current operating systems and/or display cards
+ actually support better than 8 bit per component output.<br>
+ <br>
+ If calibration curves are created for a display in which VideoLUTs
+ are not available, then the resulting calibration file will be
+ marked to indicate this, and a subsequent profile created with the
+ calibration will not have the calibration converted to the 'vcgt'
+ tag, since such a tag can't be loaded into the displays VideoLUTs.<br>
+ <br>
+ If communications break down with a USB connected instrument, you
+ may have to unplug it, and plug it in again to recover operation.<br>
+ <br>
+ Some systems (Apple OSX in particular) have a special set of user
+ interface controls ("Universal Access") that allows altering the
+ display in ways designed to assist visually impaired users, by
+ increasing contrast etc. This will interfere badly with any attempts
+ to calibrate or profile such a system, and must be turned off in
+ order to do so. Note that certain magic keyboard sequences can turn
+ this on by accident.<br>
+ <br>
+ <br>
+ <br>
+ <br>
+ <br>
+ </body>
+</html>