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| -rw-r--r-- | doc/dispcal.html | 2836 |
1 files changed, 1418 insertions, 1418 deletions
diff --git a/doc/dispcal.html b/doc/dispcal.html index ff96ff2..d66caf5 100644 --- a/doc/dispcal.html +++ b/doc/dispcal.html @@ -1,28 +1,28 @@ -<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
-<html>
- <head>
- <title>dispcal</title>
- <meta http-equiv="content-type" content="text/html;
- charset=windows-1252">
- <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;"> </span><a
- style="font-family: monospace;" href="#v">-v [n]</a><span
- style="font-family: monospace;">
+<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> +<html> + <head> + <title>dispcal</title> + <meta http-equiv="content-type" content="text/html; + charset=windows-1252"> + <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;"> </span><a + style="font-family: monospace;" href="#v">-v [n]</a><span + style="font-family: monospace;"> @@ -70,18 +70,18 @@ -
- Verbose mode<br>
- </span></font><font size="-1"><span style="font-family:
- monospace;"> </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;"> <a href="#dnm">-d n[,m]</a>
-
- [X11 only]Choose the display from the following list (default
- 1),<br>
+ + Verbose mode<br> + </span></font><font size="-1"><span style="font-family: + monospace;"> </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;"> <a href="#dnm">-d n[,m]</a> + + [X11 only]Choose the display from the following list (default + 1),<br> and optionally @@ -137,9 +137,9 @@ for -
- VideoLUT access.</span></font><br>
- <font size="-1"><span style="font-family: monospace;"> <a
+ + VideoLUT access.</span></font><br> + <font size="-1"><span style="font-family: monospace;"> <a href="#d">-d n</a> Choose the @@ -195,8 +195,8 @@ list -
- 1)</span></font><br>
+ + 1)</span></font><br> <span style="font-family: monospace;"> <a href="#dweb">-dweb[:port]</a> @@ -243,9 +243,9 @@ list -
- Display via a web server at port (default 8080)</span><br>
- <span style="font-family: monospace;"> <a href="#dmadvr">-dmadvr</a>
+ + Display via a web server at port (default 8080)</span><br> + <span style="font-family: monospace;"> <a href="#dmadvr">-dmadvr</a> @@ -276,8 +276,8 @@ list -
- [MSWin] Display via MadVR Video Renderer</span><br>
+ + [MSWin] Display via MadVR Video Renderer</span><br> <tt> </tt><tt><a href="#dcc">-dcc[:n]</a> @@ -288,13 +288,13 @@ list -
- </tt><tt>Display via n'th ChromeCast (default 1, ? for list)</tt><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> <span style="font-family: monospace;"></span></font><small
- style="font-family: monospace;"><span style="font-family:
+ + </tt><tt>Display via n'th ChromeCast (default 1, ? for list)</tt><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> <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 @@ -342,37 +342,37 @@ list -
- listno</a><span style="font-family: monospace;">
- Set communication port from
- the following list (default 1)<br>
- </span></small><font size="-1"><span style="font-family:
- monospace;"> </span><a style="font-family: monospace;"
- href="#r">-r</a><span style="font-family: monospace;">
-
- 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;"> </span><a style="font-family: monospace;"
- href="#R">-R</a><span style="font-family: monospace;">
-
- 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;"> </span><a
- style="font-family: monospace;" href="#m">-m</a><span
- style="font-family: monospace;">
-
- </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>
- <font size="-1"><span style="font-family: monospace;"><a
- href="#o">-o [profile.icm]</a> Create
- fast matrix/shaper profile [different filename to outfile.icm]<br>
+ + listno</a><span style="font-family: monospace;"> + Set communication port from + the following list (default 1)<br> + </span></small><font size="-1"><span style="font-family: + monospace;"> </span><a style="font-family: monospace;" + href="#r">-r</a><span style="font-family: monospace;"> + + 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;"> </span><a style="font-family: monospace;" + href="#R">-R</a><span style="font-family: monospace;"> + + 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;"> </span><a + style="font-family: monospace;" href="#m">-m</a><span + style="font-family: monospace;"> + + </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> + <font size="-1"><span style="font-family: monospace;"><a + href="#o">-o [profile.icm]</a> Create + fast matrix/shaper profile [different filename to outfile.icm]<br> <a href="#O">-O description</a> @@ -420,8 +420,8 @@ list -
- Fast ICC Profile Description string (Default "outfile")<br>
+ + Fast ICC Profile Description string (Default "outfile")<br> <a href="#u">-u</a> Update previous @@ -477,12 +477,12 @@ 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;"> </span><a
- style="font-family: monospace;" href="#q">-q [lmh]</a><span
+ + 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;"> </span><a + style="font-family: monospace;" href="#q">-q [lmh]</a><span style="font-family: monospace;"> @@ -530,8 +530,8 @@ ICC -
- Quality - Low, Medium (def), High<br>
+ + Quality - Low, Medium (def), High<br> <a href="#p">-p</a> @@ -568,10 +568,10 @@ ICC -
- Use telephoto mode (ie. for a projector) (if available)<br>
- </span></font><font size="-1"><span style="font-family:
- monospace;"><a href="#y">-y X</a>
+ + Use telephoto mode (ie. for a projector) (if available)<br> + </span></font><font size="-1"><span style="font-family: + monospace;"><a href="#y">-y X</a> @@ -619,12 +619,12 @@ ICC -
- 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;"> </span><a
- style="font-family: monospace;" href="#t">-t [temp]</a><span
+ + 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;"> </span><a + style="font-family: monospace;" href="#t">-t [temp]</a><span style="font-family: monospace;"> White Daylight @@ -680,10 +680,10 @@ in -
- deg. K (deflt.)<br>
- </span></font><font size="-1"><span style="font-family:
- monospace;"> </span><a style="font-family: monospace;"
+ + deg. K (deflt.)<br> + </span></font><font size="-1"><span style="font-family: + monospace;"> </span><a style="font-family: monospace;" href="#T">-T [temp]</a><span style="font-family: monospace;"> White Black @@ -739,11 +739,11 @@ 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;"> </span><a
- style="font-family: monospace;" href="#w">-w x,y</a><span
+ + in deg. K</span></font><br style="font-family: monospace;"> + <font size="-1"><span style="font-family: monospace;"></span><span + style="font-family: monospace;"> </span><a + style="font-family: monospace;" href="#w">-w x,y</a><span style="font-family: monospace;"> @@ -791,11 +791,11 @@ temperaturee -
- Set the target white point as chromaticity coordinates</span><br
- style="font-family: monospace;">
- <span style="font-family: monospace;"> </span><a
- style="font-family: monospace;" href="#b">-b bright</a><span
+ + Set the target white point as chromaticity coordinates</span><br + style="font-family: monospace;"> + <span style="font-family: monospace;"> </span><a + style="font-family: monospace;" href="#b">-b bright</a><span style="font-family: monospace;"> @@ -843,11 +843,11 @@ temperaturee -
- Set the target white brightness in cd/m^2</span><br
- style="font-family: monospace;">
- <span style="font-family: monospace;"> </span><a
- style="font-family: monospace;" href="#g">-g gamma</a><span
+ + Set the target white brightness in cd/m^2</span><br + style="font-family: monospace;"> + <span style="font-family: monospace;"> </span><a + style="font-family: monospace;" href="#g">-g gamma</a><span style="font-family: monospace;"> @@ -895,9 +895,9 @@ temperaturee -
- Set the target response curve gamma (Def. 2.4)</span><br
- style="font-family: monospace;">
+ + Set the target response curve gamma (Def. 2.4)</span><br + style="font-family: monospace;"> <span style="font-family: monospace;"> @@ -945,9 +945,9 @@ temperaturee -
- Use "-gl" for L*a*b* curve</span><br style="font-family:
- monospace;">
+ + Use "-gl" for L*a*b* curve</span><br style="font-family: + monospace;"> <span style="font-family: monospace;"> @@ -995,8 +995,8 @@ temperaturee -
- Use "-gs" for sRGB curve<br>
+ + Use "-gs" for sRGB curve<br> Use "-g709" @@ -1052,8 +1052,8 @@ use -
- -a as well!)<br>
+ + -a as well!)<br> @@ -1101,9 +1101,9 @@ use -
- Use "-g240" for SMPTE 240M curve </span></font><font size="-1"><span
- style="font-family: monospace;">(should use -a as well!)</span></font><br>
+ + 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;"> @@ -1151,7 +1151,7 @@ use -
+ Use "-G2.4 -f0" for BT.1886</span></font> @@ -1192,13 +1192,13 @@ use -
- <br>
- <font size="-1"><span style="font-family: monospace;"> </span><a
- style="font-family: monospace;" href="#G">-G gamma</a><span
- style="font-family: monospace;">
-
- Set the target response curve actual technical gamma<br>
+ + <br> + <font size="-1"><span style="font-family: monospace;"> </span><a + style="font-family: monospace;" href="#G">-G gamma</a><span + style="font-family: monospace;"> + + Set the target response curve actual technical gamma<br> <a href="#f">-f [degree]</a> Amount of @@ -1254,8 +1254,8 @@ output -
- offset (default all output offset)<br>
+ + offset (default all output offset)<br> <a href="#a">-a ambient</a> @@ -1303,17 +1303,17 @@ output -
- Use viewing condition adjustment for ambient in Lux<br>
- </span></font><font size="-1"><span style="font-family:
- monospace;"> <a href="#k">-k factor</a>
-
- 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;"> <a href="#A">-A rate</a>
-
- Rate of blending from neutral to black point. Default 4.0<br>
+ + Use viewing condition adjustment for ambient in Lux<br> + </span></font><font size="-1"><span style="font-family: + monospace;"> <a href="#k">-k factor</a> + + 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;"> <a href="#A">-A rate</a> + + Rate of blending from neutral to black point. Default 4.0<br> <a href="#bhack">-b</a> @@ -1322,10 +1322,10 @@ output -
- Use forced black point hack<br>
- </span></font> <font size="-1"><span style="font-family:
- monospace;"> </span><a style="font-family: monospace;"
+ + Use forced black point hack<br> + </span></font> <font size="-1"><span style="font-family: + monospace;"> </span><a style="font-family: monospace;" href="#B">-B bkbright</a><span style="font-family: monospace;"> @@ -1373,12 +1373,12 @@ output -
- 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;"> </span><a
- style="font-family: monospace;" href="#e">-e [n]</a><span
+ + 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;"> </span><a + style="font-family: monospace;" href="#e">-e [n]</a><span style="font-family: monospace;"> @@ -1426,12 +1426,12 @@ output -
- Run n verify passes on final curves<br>
- </span></font><font size="-1"><span style="font-family:
- monospace;"> </span><a style="font-family: monospace;"
- href="#z">-<font size="-1">z</font></a><span style="font-family:
- monospace;">
+ + Run n verify passes on final curves<br> + </span></font><font size="-1"><span style="font-family: + monospace;"> </span><a style="font-family: monospace;" + href="#z">-<font size="-1">z</font></a><span style="font-family: + monospace;"> @@ -1479,13 +1479,13 @@ output -
- 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;"> <a href="#P">-P
- ho,vo,ss[,vs]</a> Position test window
- and scale it</span><br style="font-family: monospace;">
+ + 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;"> <a href="#P">-P + ho,vo,ss[,vs]</a> Position test window + and scale it</span><br style="font-family: monospace;"> <span style="font-family: monospace;"> ho,vi: 0.0 @@ -1541,8 +1541,8 @@ center, -
- = right/bottom etc.</span><br style="font-family: monospace;">
+ + = right/bottom etc.</span><br style="font-family: monospace;"> <span style="font-family: monospace;"> ss: 0.5 @@ -1598,9 +1598,9 @@ normal, -
- = double etc.<br>
- </span></font><font size="-1"><span style="font-family:
+ + = double etc.<br> + </span></font><font size="-1"><span style="font-family: monospace;"> @@ -1635,10 +1635,10 @@ normal, -
- ss,vs: = optional horizontal, vertical scale.</span></font><br>
- <font size="-1"><span style="font-family: monospace;"> <a
- href="#F">-F</a>
+ + ss,vs: = optional horizontal, vertical scale.</span></font><br> + <font size="-1"><span style="font-family: monospace;"> <a + href="#F">-F</a> @@ -1686,11 +1686,11 @@ normal, -
- Fill whole screen with black background</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;"><a href="#E">-E</a>
+ + Fill whole screen with black background</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;"><a href="#E">-E</a> @@ -1717,13 +1717,13 @@ normal, -
- </span></font><small><span style="font-family: monospace;">Video
- encode output as (16-235)/255 "TV" levels</span></small><br
- style="font-family: monospace;">
- <font size="-1"><span style="font-family: monospace;"></span><span
- style="font-family: monospace;"> </span><a
- style="font-family: monospace;" href="#n">-n</a><span
+ + </span></font><small><span style="font-family: monospace;">Video + encode output as (16-235)/255 "TV" levels</span></small><br + style="font-family: monospace;"> + <font size="-1"><span style="font-family: monospace;"></span><span + style="font-family: monospace;"> </span><a + style="font-family: monospace;" href="#n">-n</a><span style="font-family: monospace;"> [X11 @@ -1779,14 +1779,14 @@ on -
- test window<br>
- </span></font><font size="-1"><span style="font-family:
- monospace;"> </span><a style="font-family: monospace;"
- href="#J">-J</a><span style="font-family: monospace;">
-
- Run instrument calibration first<br>
- </span></font><font size="-1"><span style="font-family:
+ + test window<br> + </span></font><font size="-1"><span style="font-family: + monospace;"> </span><a style="font-family: monospace;" + href="#J">-J</a><span style="font-family: monospace;"> + + Run instrument calibration first<br> + </span></font><font size="-1"><span style="font-family: monospace;"> <a href="#N">-N</a> @@ -1834,18 +1834,18 @@ on -
- Disable initial calibration of instrument if possible</span></font><br>
- <font size="-1"><span style="font-family: monospace;"> </span><a
- style="font-family: monospace;" href="#H">-H</a><span
- style="font-family: monospace;">
-
- Use high resolution spectrum mode (if
- available)<br>
- </span></font><font size="-1"><span style="font-family:
- monospace;"></span><span style="font-family: monospace;"><br>
- </span></font><font size="-1"><span style="font-family:
- monospace;"><span style="text-decoration: underline;"></span><a
+ + Disable initial calibration of instrument if possible</span></font><br> + <font size="-1"><span style="font-family: monospace;"> </span><a + style="font-family: monospace;" href="#H">-H</a><span + style="font-family: monospace;"> + + Use high resolution spectrum mode (if + available)<br> + </span></font><font size="-1"><span style="font-family: + monospace;"></span><span style="font-family: monospace;"><br> + </span></font><font size="-1"><span style="font-family: + monospace;"><span style="text-decoration: underline;"></span><a href="#X1">-X file.ccmx</a> @@ -1893,9 +1893,9 @@ on -
- Apply Colorimeter Correction Matrix</span></font><br>
- <span style="font-family: monospace;"> <a href="#X2">-X
+ + Apply Colorimeter Correction Matrix</span></font><br> + <span style="font-family: monospace;"> <a href="#X2">-X file.ccss</a> Use Colorimeter @@ -1946,14 +1946,14 @@ Calibration -
- Spectral Samples for calibration</span><font size="-1"><span
- style="font-family: monospace;"><br>
- </span></font><small><span style="font-family: monospace;"> </span><a
- style="font-family: monospace;" href="#Q">-Q <i>observ</i></a><span
- style="font-family: monospace;">
- Choose CIE Observer for spectrometer or CCSS
- colorimeter data:</span><br style="font-family: monospace;">
+ + Spectral Samples for calibration</span><font size="-1"><span + style="font-family: monospace;"><br> + </span></font><small><span style="font-family: monospace;"> </span><a + style="font-family: monospace;" href="#Q">-Q <i>observ</i></a><span + style="font-family: monospace;"> + Choose CIE Observer for spectrometer or CCSS + colorimeter data:</span><br style="font-family: monospace;"> <span style="font-family: monospace;"> @@ -2001,11 +2001,11 @@ Calibration -
- 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, 1964_10c<br>
+ + 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, 1964_10c<br> <a href="#I">-I b|w</a> @@ -2053,8 +2053,8 @@ Calibration -
- Drift compensation, Black: -Ib, White: -Iw, Both: -Ibw</span></small><br>
+ + Drift compensation, Black: -Ib, White: -Iw, Both: -Ibw</span></small><br> <small><span style="font-family: monospace;"><tt> <a href="#YR">-Y @@ -2071,7 +2071,7 @@ Calibration -
+ R:<i>rate</i></a> @@ -2088,36 +2088,36 @@ Calibration -
- Override measured refresh rate with rate Hz<br>
- </tt> </span></small><font size="-1"><span
- style="font-family: monospace;"></span><a style=" font-family:
- monospace;" href="#YA">-<font size="-1">Y</font> A</a><span
- style="font-family: monospace;">
-
- Use non-adaptive integration time mode (if
- available).</span></font><br>
- <font size="-1"><span style="font-family: monospace;"> </span><a
- style=" font-family: monospace;" href="#Yp">-<font size="-1">Y</font>
- <font size="-1">p</font></a><span style="font-family:
- monospace;">
-
- Don't wait for the instrument to be placed on
- the display</span></font><br>
- <small><span style="font-family: monospace;"> </span></small><font
- size="-1"><span style="font-family: monospace;"> </span><a
- style="font-family: monospace;" href="#C">-C "command"</a><span
- style="font-family: monospace;">
- Invoke shell
- "command" each time a color is set</span></font><br>
- <font size="-1"><span style="font-family: monospace;"> </span><a
- style="font-family: monospace;" href="#M">-M "command"</a><span
- style="font-family: monospace;">
- 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;"> <a
+ + Override measured refresh rate with rate Hz<br> + </tt> </span></small><font size="-1"><span + style="font-family: monospace;"></span><a style=" font-family: + monospace;" href="#YA">-<font size="-1">Y</font> A</a><span + style="font-family: monospace;"> + + Use non-adaptive integration time mode (if + available).</span></font><br> + <font size="-1"><span style="font-family: monospace;"> </span><a + style=" font-family: monospace;" href="#Yp">-<font size="-1">Y</font> + <font size="-1">p</font></a><span style="font-family: + monospace;"> + + Don't wait for the instrument to be placed on + the display</span></font><br> + <small><span style="font-family: monospace;"> </span></small><font + size="-1"><span style="font-family: monospace;"> </span><a + style="font-family: monospace;" href="#C">-C "command"</a><span + style="font-family: monospace;"> + Invoke shell + "command" each time a color is set</span></font><br> + <font size="-1"><span style="font-family: monospace;"> </span><a + style="font-family: monospace;" href="#M">-M "command"</a><span + style="font-family: monospace;"> + 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;"> <a href="#W">-W n|h|x</a> Override serial @@ -2173,12 +2173,12 @@ 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;"> </span><a
- style="font-family: monospace;" href="#D">-D [level]</a><span
+ + 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;"> </span><a + style="font-family: monospace;" href="#D">-D [level]</a><span style="font-family: monospace;"> @@ -2226,12 +2226,12 @@ none, -
- 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;"> </span><a
- style="font-family: monospace;" href="#p1"><i>inoutfile</i></a><span
+ + 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;"> </span><a + style="font-family: monospace;" href="#p1"><i>inoutfile</i></a><span style="font-family: monospace;"> @@ -2279,79 +2279,79 @@ none, -
- </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;"> 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.
- 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. 2 will
- give per step adjustment and repeat information, while 3 will give
- even greater technical detail.<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
+ + </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;"> 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. + 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. 2 will + give per step adjustment and repeat information, while 3 will give + even greater technical detail.<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 @@ -2399,273 +2399,273 @@ none, -
- 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. You may
- have to modify any firewall to permit port 8080 to be accessed on
- your machine.<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="dmadvr"></a><span style="font-weight: bold;">-dmadvr</span>
- [MSWin only] causes test patches to be displayed using the MadVR
- video renderer. Note that will have to start <b>MadTPG</b> before
- running dispcal, and that while you can adjust the "Test Pattern
- Configuration" controls, you should <u>not</u> normally alter the
- "Existing Calibration" controls, as dispcal will set these
- appropriately. <br>
- <br>
- <a name="dcc"></a><span style="font-weight: bold;">-dcc</span> or <b>-dcc:<i>no</i></b>
- causes test patches to be displayed using and available <a
- href="http://en.wikipedia.org/wiki/Chromecast">ChromeCast</a> to
- your TV. Use <b>-dcc:?</b> to display a list of ChromeCasts on your
- local network. Note that the ChromeCast as a test patch source is
- probably the<b> least accurate</b> of your choices, since it
- up-samples the test patch and transforms from RGB to YCC and back,
- but should be accurate within ± 1 bit. You may have to modify any
- firewall to permit port 8081 to be accessed on your machine if it
+ + 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. You may + have to modify any firewall to permit port 8080 to be accessed on + your machine.<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="dmadvr"></a><span style="font-weight: bold;">-dmadvr</span> + [MSWin only] causes test patches to be displayed using the MadVR + video renderer. Note that will have to start <b>MadTPG</b> before + running dispcal, and that while you can adjust the "Test Pattern + Configuration" controls, you should <u>not</u> normally alter the + "Existing Calibration" controls, as dispcal will set these + appropriately. <br> + <br> + <a name="dcc"></a><span style="font-weight: bold;">-dcc</span> or <b>-dcc:<i>no</i></b> + causes test patches to be displayed using and available <a + href="http://en.wikipedia.org/wiki/Chromecast">ChromeCast</a> to + your TV. Use <b>-dcc:?</b> to display a list of ChromeCasts on your + local network. Note that the ChromeCast as a test patch source is + probably the<b> least accurate</b> of your choices, since it + up-samples the test patch and transforms from RGB to YCC and back, + but should be accurate within ± 1 bit. You may have to modify any + firewall to permit port 8081 to be accessed on your machine if it falls back to the Default receiver (see <a href="Installing.html">installation -
- instructions</a> for your platform).<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, and in the case of MadVR renderer
- test patch display the Color Management 3dLut. If <span
- style="font-weight: bold;">-R</span> is use, then the uncalibrated
- ("raw" or "native") behaviour is measured (ie. no VideoLut or CM).
- Reported are: <br>
- <br>
- Black Brightness in cd/m^2<br>
- White Brightness in cd/m^2<br>
- The approximate Gamma<br>
- The white point x,y chromaticity co-ordinates<br>
- The correlated color temperature in Kelvin, and
- the CIEDE200 to the Black Body locus.<br>
- The correlated Daylight temperature in Kelvin,
- and the CIEDE200 to the Daylight locus.<br>
- The visual color temperature in Kelvin, and the
- CIEDE200 to the Black Body locus.<br>
- The visual Daylight temperature in Kelvin, and
- the CIEDE200 to the Daylight locus.<br>
- The visual color temperature in Kelvin<br>
- (for <span style="font-weight: bold;">-R </span>"raw":)<br>
- 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> 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> 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="ccxxmake.html">ccxxmake</a>, and installed using <a
- href="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 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> 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> An
- alternative to specifying a 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> 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>
+ + instructions</a> for your platform).<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, and in the case of MadVR renderer + test patch display the Color Management 3dLut. If <span + style="font-weight: bold;">-R</span> is use, then the uncalibrated + ("raw" or "native") behaviour is measured (ie. no VideoLut or CM). + Reported are: <br> + <br> + Black Brightness in cd/m^2<br> + White Brightness in cd/m^2<br> + The approximate Gamma<br> + The white point x,y chromaticity co-ordinates<br> + The correlated color temperature in Kelvin, and + the CIEDE200 to the Black Body locus.<br> + The correlated Daylight temperature in Kelvin, + and the CIEDE200 to the Daylight locus.<br> + The visual color temperature in Kelvin, and the + CIEDE200 to the Black Body locus.<br> + The visual Daylight temperature in Kelvin, and + the CIEDE200 to the Daylight locus.<br> + The visual color temperature in Kelvin<br> + (for <span style="font-weight: bold;">-R </span>"raw":)<br> + 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> 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> 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="ccxxmake.html">ccxxmake</a>, and installed using <a + href="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 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> 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> An + alternative to specifying a 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> 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> Set @@ -2714,14 +2714,14 @@ 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
+ + 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 @@ -2770,65 +2770,65 @@ 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
- <http://www.color.org/sRGB.xalter> 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. Both situations might be the
- case, depending on how source material is created!<br>
- <br>
+ + 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 + <http://www.color.org/sRGB.xalter> 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. 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> As @@ -2877,99 +2877,99 @@ 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) 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 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 ratio 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). For applications where maximum contrast ratio
- is important (such as <b>Video</b>), use <b>-k0</b>. <br>
- <br>
+ + 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) 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 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 ratio 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). For applications where maximum contrast ratio + is important (such as <b>Video</b>), use <b>-k0</b>. <br> + <br> <a name="A"></a><span style="font-weight: bold;">-A rate</span>: If @@ -3018,641 +3018,641 @@ 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="bhack"></a>The <b>-b</b> flag forces source 0,0,0 to map
- to destination 0,0,0. This may be useful with displays that have a
- very dark black point, and with an instrument is unable to measure
- it precisely, and where it is known in some other way that the
- display is <u>very well behaved</u> from black (i.e. that it has no
- "dead zone" above zero device input). Using this option with a
- display that is <u>not</u> well behaved, may result in a loss of
- shadow detail. This will override any <b>-k</b> factor.<br>
- <br>
- <a name="B"></a><span style="font-weight: bold;">-B</span> Set
- the target brightness of black in cd/m^2 (i.e. the absolute Y
- value). 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
- & 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="z"></a><span style="font-weight: bold;">-z</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;">-z</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, or 10% of the width of the
- display if the display size is unknown.. 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="E"></a> The <span style="font-weight: bold;">-E</span>
- flag causes the display test values to be scaled to the Video RGB
- encoding range of (16-235)/255. This also modifies the resulting
- calibration curve behavior downstream of dispcal. If a calibration
- curve created using -E gets installed or converted to an ICC profile
- 'vcgt' tag in the process of creating a profile in dispcal or
- colprof, the incoming full range values will first have the
- calibration curve applied and then be scaled to the Video encoding
- range (16-235)/255.<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 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 &
- Spyder 5</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> 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>
- <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(λ) 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="YR"></a> The -<span style="font-weight: bold;">Y R:<i>rate</i></span>
- options overrides calibration of the instrument refresh rate. This
- may be useful if the instrument supports this function and the
- refresh rate cannot be accurately calibrated from the display
- itself.<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,
- ColorMunki, i1d3 and K10. 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 faster measurement times, but
- may also give less accurate low level readings.<br>
- <br>
- <a name="Yp"></a> The -<span style="font-weight: bold;">Y p</span>
- option skips asking the user to place the instrument on the display.
- Normally a grey patch is displayed, and then the user is asked to
- confirm that the instrument is in place, so that readings can
- commence. This flag disables that check. This may be useful in
- automating certain operations.<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
- & 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 & 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>
- 1) Black level (CRT: Brightness)<br>
- 2) White point (Color temperature, R,G,B, Gain/Contrast)<br>
- 3) White level (CRT: Gain/Contrast, LCD:
- Brightness/Backlight)<br>
- 4) Black point (R,G,B, Offset/Brightness)<br>
- 5) Check all<br>
- 6) Measure and set ambient for viewing condition adjustment<br>
- 7) Continue on to calibration<br>
- 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;"> Adjust CRT brightness to get target level.
- Press space when done.</span><br style="font-family: monospace;">
- <span style="font-family: monospace;"> Target
- 0.60</span><br style="font-family: monospace;">
- <span style="font-family: monospace;"> / Current 0.68
- -</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 '=' 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>
- <small style="font-weight: bold;"><span
- style="font-family: monospace;">Adjust R,G & B gain to get
- target x,y. Press space when done.<br>
- Target B 60.00, x 0.3451, y 0.3516<br>
- / Current B 60.05, x 0.3426, y 0.3506 DE
- 1.4 R+ G+ 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 & B gain to desired white point.
- Press space when done.</span><br style="font-family: monospace;">
- <span style="font-family: monospace;"> Initial B 47.25, x
- 0.3417, y 0.3456, CDT 5113 DE 6.9</span><br
- style="font-family: monospace;">
- <span style="font-family: monospace;">\ Current B 47.38, x 0.3420,
- y 0.3460 CDT 5104 DE 6.7 R-- G+ B-</span></small><br>
- <br>
- 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>
- <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>
- Target 60.00<br>
- / Current 59.96 +</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;"> 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 '=' 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;"> Adjust R,G & B offsets to get target x,y.
- Press space when done.<br>
- Target B 0.60, x 0.3451, y 0.3516<br>
- \ Current B 0.62, x 0.2782, y 0.2331 DE
- 10.3 R+ 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% 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. If targets
- have been set, it will be like:<br>
- <br>
- <small style="font-weight: bold;"><span style="font-family:
- monospace;"> Target Brightness = 50.00, Current = 47.44,
- error = -5.1%<br>
- Target 50% Level = 10.32, Current = 8.10,
- error = -4.4%<br>
- Target Near Black = 0.47, Current = 0.68,
- error = 0.4%<br>
- Target white = x 0.3458, y 0.3586, Current = x 0.3420, y
- 0.3454, error = 7.55 DE<br>
- 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;"> Current Brightness = 46.28</span><br
- style="font-family: monospace;">
- <span style="font-family: monospace;"> Target 50%
- Level = 10.07, Current = 7.52, error = -5.5%</span><br
- style="font-family: monospace;">
- <span style="font-family: monospace;"> Target Near Black
- = 0.46, Current = 0.46, error = -0.0%</span><br
- style="font-family: monospace;">
- <span style="font-family: monospace;"> Current white = x
- 0.3439, y 0.3466, VCT 5098K DE 3.0</span><br
- style="font-family: monospace;">
- <span style="font-family: monospace;"> 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 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 OS X 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>
+ + 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="bhack"></a>The <b>-b</b> flag forces source 0,0,0 to map + to destination 0,0,0. This may be useful with displays that have a + very dark black point, and with an instrument is unable to measure + it precisely, and where it is known in some other way that the + display is <u>very well behaved</u> from black (i.e. that it has no + "dead zone" above zero device input). Using this option with a + display that is <u>not</u> well behaved, may result in a loss of + shadow detail. This will override any <b>-k</b> factor.<br> + <br> + <a name="B"></a><span style="font-weight: bold;">-B</span> Set + the target brightness of black in cd/m^2 (i.e. the absolute Y + value). 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 + & 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="z"></a><span style="font-weight: bold;">-z</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;">-z</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, or 10% of the width of the + display if the display size is unknown.. 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="E"></a> The <span style="font-weight: bold;">-E</span> + flag causes the display test values to be scaled to the Video RGB + encoding range of (16-235)/255. This also modifies the resulting + calibration curve behavior downstream of dispcal. If a calibration + curve created using -E gets installed or converted to an ICC profile + 'vcgt' tag in the process of creating a profile in dispcal or + colprof, the incoming full range values will first have the + calibration curve applied and then be scaled to the Video encoding + range (16-235)/255.<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 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 & + Spyder 5</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> 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> + <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(λ) 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="YR"></a> The -<span style="font-weight: bold;">Y R:<i>rate</i></span> + options overrides calibration of the instrument refresh rate. This + may be useful if the instrument supports this function and the + refresh rate cannot be accurately calibrated from the display + itself.<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, + ColorMunki, i1d3 and K10. 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 faster measurement times, but + may also give less accurate low level readings.<br> + <br> + <a name="Yp"></a> The -<span style="font-weight: bold;">Y p</span> + option skips asking the user to place the instrument on the display. + Normally a grey patch is displayed, and then the user is asked to + confirm that the instrument is in place, so that readings can + commence. This flag disables that check. This may be useful in + automating certain operations.<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 + & 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 & 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> + 1) Black level (CRT: Brightness)<br> + 2) White point (Color temperature, R,G,B, Gain/Contrast)<br> + 3) White level (CRT: Gain/Contrast, LCD: + Brightness/Backlight)<br> + 4) Black point (R,G,B, Offset/Brightness)<br> + 5) Check all<br> + 6) Measure and set ambient for viewing condition adjustment<br> + 7) Continue on to calibration<br> + 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;"> Adjust CRT brightness to get target level. + Press space when done.</span><br style="font-family: monospace;"> + <span style="font-family: monospace;"> Target + 0.60</span><br style="font-family: monospace;"> + <span style="font-family: monospace;"> / Current 0.68 + -</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 '=' 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> + <small style="font-weight: bold;"><span + style="font-family: monospace;">Adjust R,G & B gain to get + target x,y. Press space when done.<br> + Target B 60.00, x 0.3451, y 0.3516<br> + / Current B 60.05, x 0.3426, y 0.3506 DE + 1.4 R+ G+ 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 & B gain to desired white point. + Press space when done.</span><br style="font-family: monospace;"> + <span style="font-family: monospace;"> Initial B 47.25, x + 0.3417, y 0.3456, CDT 5113 DE 6.9</span><br + style="font-family: monospace;"> + <span style="font-family: monospace;">\ Current B 47.38, x 0.3420, + y 0.3460 CDT 5104 DE 6.7 R-- G+ B-</span></small><br> + <br> + 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> + <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> + Target 60.00<br> + / Current 59.96 +</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;"> 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 '=' 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;"> Adjust R,G & B offsets to get target x,y. + Press space when done.<br> + Target B 0.60, x 0.3451, y 0.3516<br> + \ Current B 0.62, x 0.2782, y 0.2331 DE + 10.3 R+ 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% 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. If targets + have been set, it will be like:<br> + <br> + <small style="font-weight: bold;"><span style="font-family: + monospace;"> Target Brightness = 50.00, Current = 47.44, + error = -5.1%<br> + Target 50% Level = 10.32, Current = 8.10, + error = -4.4%<br> + Target Near Black = 0.47, Current = 0.68, + error = 0.4%<br> + Target white = x 0.3458, y 0.3586, Current = x 0.3420, y + 0.3454, error = 7.55 DE<br> + 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;"> Current Brightness = 46.28</span><br + style="font-family: monospace;"> + <span style="font-family: monospace;"> Target 50% + Level = 10.07, Current = 7.52, error = -5.5%</span><br + style="font-family: monospace;"> + <span style="font-family: monospace;"> Target Near Black + = 0.46, Current = 0.46, error = -0.0%</span><br + style="font-family: monospace;"> + <span style="font-family: monospace;"> Current white = x + 0.3439, y 0.3466, VCT 5098K DE 3.0</span><br + style="font-family: monospace;"> + <span style="font-family: monospace;"> 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 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 OS X 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> |