From 3db384424bd7398ffbb7a355cab8f15f3add009f Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?J=C3=B6rg=20Frings-F=C3=BCrst?= Date: Sun, 2 Oct 2016 19:24:58 +0200 Subject: New upstream version 1.9.1+repack --- doc/dispcal.html | 2836 +++++++++++++++++++++++++++--------------------------- 1 file changed, 1418 insertions(+), 1418 deletions(-) (limited to 'doc/dispcal.html') diff --git a/doc/dispcal.html b/doc/dispcal.html index d66caf5..ff96ff2 100644 --- a/doc/dispcal.html +++ b/doc/dispcal.html @@ -1,28 +1,28 @@ - - - - dispcal - - - - -

spectro/dispcal

-

Summary

- 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.
-

Usage

- dispcal - [-options] inoutfile
-  -v [n] + + + + dispcal + + + + +

spectro/dispcal

+

Summary

+ 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.
+

Usage

+ dispcal + [-options] inoutfile
+  -v [n]               @@ -70,18 +70,18 @@ - - Verbose mode
-  -display displayname [X11 only] Choose X11 display - name
-  -d n[,m] -             - [X11 only]Choose the display from the following list (default - 1),
+ + Verbose mode
+  -display displayname [X11 only] Choose X11 display + name
+  -d n[,m] +             + [X11 only]Choose the display from the following list (default + 1),
                      and optionally @@ -137,9 +137,9 @@ for - - VideoLUT access.
-  
+  -d n                 Choose the @@ -195,8 +195,8 @@ list - - 1)
+ + 1)
 -dweb[:port]         @@ -243,9 +243,9 @@ list - - Display via a web server at port (default 8080)
-  -dmadvr + + Display via a web server at port (default 8080)
+  -dmadvr              @@ -276,8 +276,8 @@ list - - [MSWin] Display via MadVR Video Renderer
+ + [MSWin] Display via MadVR Video Renderer
 -dcc[:n]             @@ -288,13 +288,13 @@ list - - Display via n'th ChromeCast (default 1, ? for list)
-   +   -c @@ -342,37 +342,37 @@ list - - listno     -        Set communication port from - the following list (default 1)
-  -r -              -      Report on the calibrated display then - exit
-  -R -              -      Report on the uncalibrated display then - exit
-  -m -              -      Skip adjustment of the monitor - controls
-   -o [profile.icm]     Create - fast matrix/shaper profile [different filename to outfile.icm]
+ + listno     +        Set communication port from + the following list (default 1)
+  -r +              +      Report on the calibrated display then + exit
+  -R +              +      Report on the uncalibrated display then + exit
+  -m +              +      Skip adjustment of the monitor + controls
+   -o [profile.icm]     Create + fast matrix/shaper profile [different filename to outfile.icm]
 -O description       @@ -420,8 +420,8 @@ list - - Fast ICC Profile Description string (Default "outfile")
+ + Fast ICC Profile Description string (Default "outfile")
 -u                   Update previous @@ -477,12 +477,12 @@ ICC - - profile VideoLUTs
-  -q [lmh]
+  -q [lmh]             @@ -530,8 +530,8 @@ ICC - - Quality - Low, Medium (def), High
+ + Quality - Low, Medium (def), High
 -p                   @@ -568,10 +568,10 @@ ICC - - Use telephoto mode (ie. for a projector) (if available)
-  -y X + + Use telephoto mode (ie. for a projector) (if available)
+  -y X                 @@ -619,12 +619,12 @@ ICC - - Display type - instrument specific list to choose from.
-  -t [temp]
+  -t [temp]            White Daylight @@ -680,10 +680,10 @@ in - - deg. K (deflt.)
-   +  -T [temp]            White Black @@ -739,11 +739,11 @@ temperaturee - - in deg. K
-  -w x,y
+  -w x,y               @@ -791,11 +791,11 @@ temperaturee - - Set the target white point as chromaticity coordinates
-  -b bright
+  -b bright            @@ -843,11 +843,11 @@ temperaturee - - Set the target white brightness in cd/m^2
-  -g gamma
+  -g gamma             @@ -895,9 +895,9 @@ temperaturee - - Set the target response curve gamma (Def. 2.4)
+ + Set the target response curve gamma (Def. 2.4)
                      @@ -945,9 +945,9 @@ temperaturee - - Use "-gl" for L*a*b* curve
+ + Use "-gl" for L*a*b* curve
               @@ -995,8 +995,8 @@ temperaturee - -        Use "-gs" for sRGB curve
+ +        Use "-gs" for sRGB curve
                      Use "-g709" @@ -1052,8 +1052,8 @@ use - - -a as well!)
+ + -a as well!)
                      @@ -1101,9 +1101,9 @@ use - - Use "-g240" for SMPTE 240M curve (should use -a as well!)
+ + Use "-g240" for SMPTE 240M curve (should use -a as well!)
                      @@ -1151,7 +1151,7 @@ use - + Use "-G2.4 -f0" for BT.1886                                           @@ -1192,13 +1192,13 @@ use - -
-  -G gamma -             - Set the target response curve actual technical gamma
+ +
+  -G gamma +             + Set the target response curve actual technical gamma
 -f [degree]          Amount of @@ -1254,8 +1254,8 @@ output - - offset (default all output offset)
+ + offset (default all output offset)
 -a ambient           @@ -1303,17 +1303,17 @@ output - - Use viewing condition adjustment for ambient in Lux
-  -k factor -            - Amount to try and correct black point hue. Default 1.0, LCD - default 0.0
-  -A rate -              - Rate of blending from neutral to black point. Default 4.0
+ + Use viewing condition adjustment for ambient in Lux
+  -k factor +            + Amount to try and correct black point hue. Default 1.0, LCD + default 0.0
+  -A rate +              + Rate of blending from neutral to black point. Default 4.0
 -b                   @@ -1322,10 +1322,10 @@ output - - Use forced black point hack
-   +  -B bkbright          @@ -1373,12 +1373,12 @@ output - - Set the target black brightness in cd/m^2
-  -e [n]
+  -e [n]               @@ -1426,12 +1426,12 @@ output - - Run n verify passes on final curves
-  -z + + Run n verify passes on final curves
+  -z                   @@ -1479,13 +1479,13 @@ output - - Run only verify pass on installed calibration curves
-  -P - ho,vo,ss[,vs]     Position test window - and scale it
+ + Run only verify pass on installed calibration curves
+  -P + ho,vo,ss[,vs]     Position test window + and scale it
                      ho,vi: 0.0 @@ -1541,8 +1541,8 @@ center, - - = right/bottom etc.
+ + = right/bottom etc.
                      ss: 0.5 @@ -1598,9 +1598,9 @@ normal, - - = double etc.
-                       @@ -1635,10 +1635,10 @@ normal, - - ss,vs: = optional horizontal, vertical scale.
-  -F + + ss,vs: = optional horizontal, vertical scale.
+  -F                   @@ -1686,11 +1686,11 @@ normal, - - Fill whole screen with black background
-  -E + + Fill whole screen with black background
+  -E                   @@ -1717,13 +1717,13 @@ normal, - - Video - encode output as (16-235)/255 "TV" levels
-  -nVideo + encode output as (16-235)/255 "TV" levels
+  -n                   [X11 @@ -1779,14 +1779,14 @@ on - - test window
-  -J -              -      Run instrument calibration first
-  -J +              +      Run instrument calibration first
+  -N                   @@ -1834,18 +1834,18 @@ on - - Disable initial calibration of instrument if possible
-  -H -              -      Use high resolution spectrum mode (if - available)
-
-  
+  -H +              +      Use high resolution spectrum mode (if + available)
+
+  -X file.ccmx         @@ -1893,9 +1893,9 @@ on - - Apply Colorimeter Correction Matrix
-  -X + + Apply Colorimeter Correction Matrix
+  -X file.ccss          Use Colorimeter @@ -1946,14 +1946,14 @@ Calibration - - Spectral Samples for calibration
-  -Q observ        -     Choose CIE Observer for spectrometer or CCSS - colorimeter data:
+ + Spectral Samples for calibration
+  -Q observ        +     Choose CIE Observer for spectrometer or CCSS + colorimeter data:
            @@ -2001,11 +2001,11 @@ Calibration - -           1931_2 (def.), 1964_10, S&B 1955_2, shaw, - J&V 1978_2, 1964_10c
+ +           1931_2 (def.), 1964_10, S&B 1955_2, shaw, + J&V 1978_2, 1964_10c
 -I b|w               @@ -2053,8 +2053,8 @@ Calibration - - Drift compensation, Black: -Ib, White: -Iw, Both: -Ibw
+ + Drift compensation, Black: -Ib, White: -Iw, Both: -Ibw
 -Y @@ -2071,7 +2071,7 @@ Calibration - + R:rate            @@ -2088,36 +2088,36 @@ Calibration - - Override measured refresh rate with rate Hz
-  -Y A -             -     Use non-adaptive integration time mode (if - available).
-  -Y - p -             -     Don't wait for the instrument to be placed on - the display
-  -C "command" -         Invoke shell - "command" each time a color is set
-  -M "command" -         Invoke shell - "command" each time a color is measured
-   +  -Y A +             +     Use non-adaptive integration time mode (if + available).
+  -Y + p +             +     Don't wait for the instrument to be placed on + the display
+  -C "command" +         Invoke shell + "command" each time a color is set
+  -M "command" +         Invoke shell + "command" each time a color is measured
+  -W n|h|x             Override serial @@ -2173,12 +2173,12 @@ none, - - h = HW, x = Xon/Xoff
-  -D [level]
+  -D [level]           @@ -2226,12 +2226,12 @@ none, - - Print debug diagnostics to stderr
-  inoutfile
+  inoutfile            @@ -2279,79 +2279,79 @@ none, - - Base name for created - or updated .cal  and .icm output files
-
-

Comments
-

- 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 -B option to black - the whole screen out, although this will make it impossible to - control dispcal unless you have more than one display.
-
- The -v 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.
-
- When running on a UNIX based system that used - the X11 Windowing System, dispcal 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 -display - option. Note that if Xinerama is active, you can't select the screen - using $DISPLAY or -display, you have to select it using the -d parameter.
-
- 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 -d parameter. If you invoke dispcal 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 -d parameter will - override the screen specified by the $DISPLAY or parameter.
-
- Note that if VideoLUTs for a - display are not accessible (i.e. no hardware calibration - capability), dispcal will - will issue a warning, but continue creating a calibration based on - the display "as-is" rather than its native response. See the -o flag for an explanation of the - implications of having no access to the VideoLUTs.
-
- 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 dispwin -r - 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.
-
- 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 + + Base name for created + or updated .cal  and .icm output files
+
+

Comments
+

+ 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 -B option to black + the whole screen out, although this will make it impossible to + control dispcal unless you have more than one display.
+
+ The -v 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.
+
+ When running on a UNIX based system that used + the X11 Windowing System, dispcal 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 -display + option. Note that if Xinerama is active, you can't select the screen + using $DISPLAY or -display, you have to select it using the -d parameter.
+
+ 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 -d parameter. If you invoke dispcal 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 -d parameter will + override the screen specified by the $DISPLAY or parameter.
+
+ Note that if VideoLUTs for a + display are not accessible (i.e. no hardware calibration + capability), dispcal will + will issue a warning, but continue creating a calibration based on + the display "as-is" rather than its native response. See the -o flag for an explanation of the + implications of having no access to the VideoLUTs.
+
+ 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 dispwin -r + 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.
+
+ 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. -d @@ -2399,273 +2399,273 @@ none, - - 1,2 . Some experimentation may be needed using dispwin 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.
-
- -dweb or - -dweb:port 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 8080 is used, but this - can be overridden by appending a : - and the port number i.e. -dweb:8001. - The URL will be http:// - then name of the machine or its I.P. address followed by a colon and - the port number - e.g something like http://192.168.0.1:8080. If you use the verbose - option (-v) then a likely - URL will be printed once the server is started, or you could run ipconfig (MSWin) or /sbin/ifconfig (Linux or OS X) - and identify an internet address for your machine that way. JavaScript - 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.
-
- 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 -o flag for an explanation of the - implications of having no access to the VideoLUTs.
-
- -dmadvr - [MSWin only] causes test patches to be displayed using the MadVR - video renderer. Note that will have to start MadTPG before - running dispcal, and that while you can adjust the "Test Pattern - Configuration" controls, you should not normally alter the - "Existing Calibration" controls, as dispcal will set these - appropriately.
-
- -dcc or -dcc:no - causes test patches to be displayed using and available ChromeCast to - your TV. Use -dcc:? to display a list of ChromeCasts on your - local network. Note that the ChromeCast as a test patch source is - probably the least accurate 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 . Some experimentation may be needed using dispwin 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.
+
+ -dweb or + -dweb:port 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 8080 is used, but this + can be overridden by appending a : + and the port number i.e. -dweb:8001. + The URL will be http:// + then name of the machine or its I.P. address followed by a colon and + the port number - e.g something like http://192.168.0.1:8080. If you use the verbose + option (-v) then a likely + URL will be printed once the server is started, or you could run ipconfig (MSWin) or /sbin/ifconfig (Linux or OS X) + and identify an internet address for your machine that way. JavaScript + 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.
+
+ 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 -o flag for an explanation of the + implications of having no access to the VideoLUTs.
+
+ -dmadvr + [MSWin only] causes test patches to be displayed using the MadVR + video renderer. Note that will have to start MadTPG before + running dispcal, and that while you can adjust the "Test Pattern + Configuration" controls, you should not normally alter the + "Existing Calibration" controls, as dispcal will set these + appropriately.
+
+ -dcc or -dcc:no + causes test patches to be displayed using and available ChromeCast to + your TV. Use -dcc:? to display a list of ChromeCasts on your + local network. Note that the ChromeCast as a test patch source is + probably the least accurate 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 installation - - instructions for your platform).
-
- -c The - instrument is assumed to communicate through a USB or serial - communication port, and the port can be selected with the -c - option, if the instrument is not connected to the first port. If you - invoke dispcal 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.
-
- The -r and - -R flags - perform a quick measurement of current display behaviour, reports - and then exits. If the -r - 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 -R is use, then the uncalibrated - ("raw" or "native") behaviour is measured (ie. no VideoLut or CM). - Reported are:
-
-     Black Brightness in cd/m^2
-     White Brightness in cd/m^2
-     The approximate Gamma
-     The white point x,y chromaticity co-ordinates
-     The correlated color temperature in Kelvin, and - the CIEDE200 to the Black Body locus.
-     The correlated Daylight temperature in Kelvin, - and the CIEDE200 to the Daylight locus.
-     The visual color temperature in Kelvin, and the - CIEDE200 to the Black Body locus.
-     The visual Daylight temperature in Kelvin, and - the CIEDE200 to the Daylight locus.
-     The visual color temperature in Kelvin
- (for -R "raw":)
-     The apparent VideoLUT entry number of significant - bits.
-
- 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.
-
- The -m - option skips the usual process of adjusting the display monitor - contrast, brightness and white point controls, and skips straight to - calibration.
-
- -o [profile.icm] Normally dispcal creates just a - calibration file, which can then be used for subsequent - characterization using dispread and - profiling using colprof. If the -o flag is used, dispcal will also create a - shaper/matrix profile. By default it will create a profile named inoutfile.icm, but a differently - named file can be created or updated by specifying the name after - the -o flag. If the -u flag is used with -o, then the ICC profile vcgt calibration curves will be - updated.
-
- 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 tutorial for a - further explanation.
-
- The -O 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.
-
- -u Normally - dispcal 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 -u 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 -o flag is used as well, then - the ICC profile will have - its vcgt tag updated with the new calibration. This keeps the - profile up to date with the display. Normally dispcal -u will use the same - quality level that was specified in the previous calibration, but - this can be overridden using the -q - 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).
-
-   Quality - Low, Medium (def), High. The -q 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).
-
- The -p 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.
-
-   The -y - flag allows setting the Display Type. The selection typically - determines two aspects of of the instrument operation: 1) It may set the measuring mode - to suite refresh or non-refresh displays. - Typically only LCD (Liquid Crystal) displays have a non-refresh - nature. 2) 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 usage - information. For more details on what particular instruments support - and how this works, see Operation of - particular instruments. 3) Any installed CCSS files - (if applicable), or CCMX files. These files are typically created - using ccxxmake, and installed using oeminst. The default and Base Calibration - types will be indicated in the usage.
-
- -t 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 -t, 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.
-
- -T  Same functionality as - the -t 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.
-
- -w  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).
-
- -b  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. NOTE - 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.
-
+ + instructions for your platform).
+
+ -c The + instrument is assumed to communicate through a USB or serial + communication port, and the port can be selected with the -c + option, if the instrument is not connected to the first port. If you + invoke dispcal 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.
+
+ The -r and + -R flags + perform a quick measurement of current display behaviour, reports + and then exits. If the -r + 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 -R is use, then the uncalibrated + ("raw" or "native") behaviour is measured (ie. no VideoLut or CM). + Reported are:
+
+     Black Brightness in cd/m^2
+     White Brightness in cd/m^2
+     The approximate Gamma
+     The white point x,y chromaticity co-ordinates
+     The correlated color temperature in Kelvin, and + the CIEDE200 to the Black Body locus.
+     The correlated Daylight temperature in Kelvin, + and the CIEDE200 to the Daylight locus.
+     The visual color temperature in Kelvin, and the + CIEDE200 to the Black Body locus.
+     The visual Daylight temperature in Kelvin, and + the CIEDE200 to the Daylight locus.
+     The visual color temperature in Kelvin
+ (for -R "raw":)
+     The apparent VideoLUT entry number of significant + bits.
+
+ 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.
+
+ The -m + option skips the usual process of adjusting the display monitor + contrast, brightness and white point controls, and skips straight to + calibration.
+
+ -o [profile.icm] Normally dispcal creates just a + calibration file, which can then be used for subsequent + characterization using dispread and + profiling using colprof. If the -o flag is used, dispcal will also create a + shaper/matrix profile. By default it will create a profile named inoutfile.icm, but a differently + named file can be created or updated by specifying the name after + the -o flag. If the -u flag is used with -o, then the ICC profile vcgt calibration curves will be + updated.
+
+ 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 tutorial for a + further explanation.
+
+ The -O 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.
+
+ -u Normally + dispcal 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 -u 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 -o flag is used as well, then + the ICC profile will have + its vcgt tag updated with the new calibration. This keeps the + profile up to date with the display. Normally dispcal -u will use the same + quality level that was specified in the previous calibration, but + this can be overridden using the -q + 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).
+
+   Quality - Low, Medium (def), High. The -q 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).
+
+ The -p 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.
+
+   The -y + flag allows setting the Display Type. The selection typically + determines two aspects of of the instrument operation: 1) It may set the measuring mode + to suite refresh or non-refresh displays. + Typically only LCD (Liquid Crystal) displays have a non-refresh + nature. 2) 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 usage + information. For more details on what particular instruments support + and how this works, see Operation of + particular instruments. 3) Any installed CCSS files + (if applicable), or CCMX files. These files are typically created + using ccxxmake, and installed using oeminst. The default and Base Calibration + types will be indicated in the usage.
+
+ -t 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 -t, 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.
+
+ -T  Same functionality as + the -t 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.
+
+ -w  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).
+
+ -b  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. NOTE + 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.
+
-g gamma  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 (-gs), the @@ -2770,65 +2770,65 @@ the - - L* curve, which is the response of the CIE L*a*b* perceptual - colorspace (-gl). the REC - 709 video standard response curve (-g709) - and the SMPTE 240M video standard response curve (-g240)
-
- Note 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 dispcal 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 -f option (see below).
-
- Also note that many color - spaces are encoded with, and labelled as having a gamma of - approximately 2.2 (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 2.4 viewed in a darkened - environment. This is because this 2.2 - 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 not what you want! 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 alternatively - use sRGB or REC 709 or a gamm of 2.2 but also use the -a - parameter to specify the actual ambient viewing conditions, so that - dispcal 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.
-
- 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!
-
+ + L* curve, which is the response of the CIE L*a*b* perceptual + colorspace (-gl). the REC + 709 video standard response curve (-g709) + and the SMPTE 240M video standard response curve (-g240)
+
+ Note 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 dispcal 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 -f option (see below).
+
+ Also note that many color + spaces are encoded with, and labelled as having a gamma of + approximately 2.2 (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 2.4 viewed in a darkened + environment. This is because this 2.2 + 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 not what you want! 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 alternatively + use sRGB or REC 709 or a gamm of 2.2 but also use the -a + parameter to specify the actual ambient viewing conditions, so that + dispcal 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.
+
+ 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!
+
-G gamma  As @@ -2877,99 +2877,99 @@ As - - explained above, the gamma value provided to the -g 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 -G option - is an alternative that allows the actual - 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.
-
- -f [degree]: - As explained in for the -g - and -G 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. 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. 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 -f degree, 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 -f - is used without a specified degree, a degree of 0.0 is assumed, the - opposite of the default. Note - that using all input offset (degree == 0.0) is equivalent to the use - of the BT.1886 transfer - function.
-
- -a ambient: - As explained for the -g - 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 -a option - is a way of doing this. By default dispcal - will not make any allowances for viewing conditions, but will - calibrate to the specified response curve, but if the -a 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.
-
- -k factor: - Normally this will be set automatically, based on the measured black - level of the display. A -k - 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 lighten 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 LCD type displays, or CRT 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 - -k factor should be used. -k 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 -A - parameter (see below). For applications where maximum contrast ratio - is important (such as Video), use -k0.
-
+ + explained above, the gamma value provided to the -g 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 -G option + is an alternative that allows the actual + 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.
+
+ -f [degree]: + As explained in for the -g + and -G 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. 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. 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 -f degree, 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 -f + is used without a specified degree, a degree of 0.0 is assumed, the + opposite of the default. Note + that using all input offset (degree == 0.0) is equivalent to the use + of the BT.1886 transfer + function.
+
+ -a ambient: + As explained for the -g + 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 -a option + is a way of doing this. By default dispcal + will not make any allowances for viewing conditions, but will + calibrate to the specified response curve, but if the -a 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.
+
+ -k factor: + Normally this will be set automatically, based on the measured black + level of the display. A -k + 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 lighten 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 LCD type displays, or CRT 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 + -k factor should be used. -k 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 -A + parameter (see below). For applications where maximum contrast ratio + is important (such as Video), use -k0.
+
-A rate:  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 -k - 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 -A 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.
-
- The -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 very well behaved from black (i.e. that it has no - "dead zone" above zero device input). Using this option with a - display that is not well behaved, may result in a loss of - shadow detail. This will override any -k factor.
-
- -B  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.
-
- -e [n] Run n 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 n, 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.
-
- -z 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. Note 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 dispwin to load a .cal file into the display - before running dispcal -z. - 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 -a parameter - for verify.
-
- The -P - 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 ho and vo 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 ss - 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 -P 1,0,2 - . To create a window twice as wide as high: -P 1,0,2,1.
-
- The -F - 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.
-
- The -E - 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.
-
- -n When - running on a UNIX based system that used the X11 Windowing System, dispcal - 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 -n - option turns this behaviour off.
-
- The -J - 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 -N - 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.
-
- -N 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 -N - 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.
-
- The -H - option turns on high resolution spectral mode, if the instrument - supports it, such as the Eye-One Pro. See Operation of particular instruments - for more details. This may give better accuracy for display - measurements.
-
- The -X file.ccmx option reads - a Colorimeter Correction Matrix - 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 ccmx files is here.
-
- The -X file.ccss option reads - a Colorimeter Calibration - Spectral Sample 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 i1d3, - or the DataColor Spyder4 & - Spyder 5).This can improve a colorimeters accuracy for a - particular type of display.
-
- The -Q 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:
-   1931_2 selects the standard CIE 1931 2 degree - observer. The default.
-   1964_10 selects the standard CIE 1964 10 degree - observer.
-   1955_2 selects the Stiles and Birch 1955 2 degree - observer
-   1978_2 selects the Judd and Voss 1978 2 degree - observer
-   shaw selects the Shaw and Fairchild 1997 2 degree - observer
-   1964_10c 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.
-
- NOTE 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.
-
- The -I b|w 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 -Ib. - If just display white level compensation is needed, use -Iw. If both are needed, use -Ibw or -Iwb.
-
- The -Y R:rate - 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.
-
- The -Y A - 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.
-
- The -Y p - 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.
-
- The -C "command" 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.
-
- The -M "command" 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 "command.meas" - 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.
-
- The -W n|h|x - parameter overrides the default serial communications flow control - setting. The value n turns - all flow control off, h - sets hardware handshaking, and x - sets Xon/Xoff handshaking. This commend may be useful in workaround - serial communications issues with some systems and cables.
-
- The -D 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.
-
- inoutfile - The final parameter on the command line is the base filename for the - .cal file and the optional ICC - profile. Normally this will be created (or an existing file will be - overwritten). If the -u - 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 -o flag.
-
- NOTE that on an X11 system, - if the environment variable ARGYLL_IGNORE_XRANDR1_2 - 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.
-
-
-

Discussion and guide to display control - adjustment:

-
- 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.
-
- Almost all LCD displays lack a real contrast 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 contrast 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 contrast - control to neutral. The LCD brightness - 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 backlight - control as well as a brightness - 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 backlight - control in place of brightness - in the following adjustments.
-
- 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.
-
- On CRT based displays, the brightness - control generally adjusts the black level of the display (sometimes - called the offset), and as - a side effect, tends to change the maximum brightness too. A CRT contrast control generally - adjusts the maximum brightness (sometimes called gain) without affecting the - black level a great deal. On a CRT both the brightness and contrast controls will tend to - affect the shape or gamma of the display response curve.
-
- 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.
-
- 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 "white point selection" or R/G/B "gain" 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.
-
- 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, dispcal - offers a menu of adjustment modes, so that the user can - interactively and iteratively adjust the display controls to meet - the desired targets.
-
-   1) Black level (CRT: Brightness)
-   2) White point (Color temperature, R,G,B, Gain/Contrast)
-   3) White level (CRT: Gain/Contrast, LCD: - Brightness/Backlight)
-   4) Black point (R,G,B, Offset/Brightness)
-   5) Check all
-   6) Measure and set ambient for viewing condition adjustment
-   7) Continue on to calibration
-   8) Exit
-
- 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 -t -T or -w options, and on whether a - brightness target has been set using the -b option.
-
-
- 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.
-
-   Adjust CRT brightness to get target level. - Press space when done.
-      Target - 0.60
-   / Current 0.68  - -
-
- Once happy with the adjustment, press space to go back to the menu.
-
-
- 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.
-
-    Adjust R,G & B gain to get - target x,y. Press space when done.
-      Target B 60.00, x 0.3451, y 0.3516
-   / Current B 60.05, x 0.3426, y 0.3506  DE  - 1.4  R+  G+  B--
-
- 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 -T 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).
-
- Adjust R,G & B gain to desired white point. - Press space when done.
-   Initial B 47.25, x - 0.3417, y 0.3456, CDT 5113 DE  6.9
- \ Current B 47.38, x 0.3420, - y 0.3460  CDT 5104 DE  6.7  R-- G+  B-
-
-  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.
-
-
- The third mode lets you adjust the brightness of white on the - display. If you set a target brightness using the -b - 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.
-
-    Adjust CRT Contrast or LCD - Brightness to get target level. Press space when done.
-      Target 60.00
-   / Current 59.96  +
-
- 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:
-
- Adjust CRT Contrast or LCD Brightness to desired - level. Press space when done.
-   Initial 47.32
- / Current 47.54
-
- Once happy with the adjustment, press space to go back to the menu.
-
-
- 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. -
-
-   Adjust R,G & B offsets to get target x,y. - Press space when done.
-      Target B 0.60, x 0.3451, y 0.3516
-   \ Current B 0.62, x 0.2782, y 0.2331  DE  - 10.3  R+  G++ B-
-
- 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.
-
-
- The fifth selection checks on the overall settings.  If targets - have been set, it will be like:
-
-   Target Brightness = 50.00, Current = 47.44, - error = -5.1%
-   Target 50% Level  = 10.32, Current =  8.10, - error = -4.4%
-   Target Near Black =  0.47, Current =  0.68, - error =  0.4%
-   Target white = x 0.3458, y 0.3586, Current = x 0.3420, y - 0.3454, error =  7.55 DE
-   Target black = x 0.3458, y 0.3586, Current = x 0.2908, y - 0.2270, error = 29.69 DE
-
- or if no targets are set:
-
-   Current Brightness = 46.28
-   Target 50% - Level  = 10.07, Current =  7.52, error = -5.5%
-   Target Near Black - =  0.46, Current =  0.46, error = -0.0%
-   Current white = x - 0.3439, y 0.3466, VCT 5098K DE  3.0
-   Target black = x - 0.3439, y 0.3466, Current = x 0.3093, y 0.2165, error = 30.30 DE
-
- and will then go back to the menu.
-
- The sixth selection 6) - allows the reading of you ambient lighting conditions if your - instrument supports such a mode. Doing so will enable the -a option to compensate for your - viewing conditions in the subsequent calibration. See -a.
-
- Once  you're happy with the display set-up, you can either - proceed on to the rest of the calibration by selecting 7), or exit and re-start by - selecting 8). You might - want to re-start if you want to change the calibration targets.
-
-
-

Other caveats:

- NOTE 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.
-
- 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.
-
- 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.
-
- 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.
-
- If communications break down with a USB connected instrument, you - may have to unplug it, and plug it in again to recover operation.
-
- 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.
-
-
-
-
-
- - + + the black point is not being set completely to the same hue as the + white point (ie. because the -k + 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 -A 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.
+
+ The -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 very well behaved from black (i.e. that it has no + "dead zone" above zero device input). Using this option with a + display that is not well behaved, may result in a loss of + shadow detail. This will override any -k factor.
+
+ -B  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.
+
+ -e [n] Run n 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 n, 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.
+
+ -z 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. Note 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 dispwin to load a .cal file into the display + before running dispcal -z. + 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 -a parameter + for verify.
+
+ The -P + 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 ho and vo 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 ss + 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 -P 1,0,2 + . To create a window twice as wide as high: -P 1,0,2,1.
+
+ The -F + 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.
+
+ The -E + 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.
+
+ -n When + running on a UNIX based system that used the X11 Windowing System, dispcal + 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 -n + option turns this behaviour off.
+
+ The -J + 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 -N + 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.
+
+ -N 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 -N + 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.
+
+ The -H + option turns on high resolution spectral mode, if the instrument + supports it, such as the Eye-One Pro. See Operation of particular instruments + for more details. This may give better accuracy for display + measurements.
+
+ The -X file.ccmx option reads + a Colorimeter Correction Matrix + 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 ccmx files is here.
+
+ The -X file.ccss option reads + a Colorimeter Calibration + Spectral Sample 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 i1d3, + or the DataColor Spyder4 & + Spyder 5).This can improve a colorimeters accuracy for a + particular type of display.
+
+ The -Q 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:
+   1931_2 selects the standard CIE 1931 2 degree + observer. The default.
+   1964_10 selects the standard CIE 1964 10 degree + observer.
+   1955_2 selects the Stiles and Birch 1955 2 degree + observer
+   1978_2 selects the Judd and Voss 1978 2 degree + observer
+   shaw selects the Shaw and Fairchild 1997 2 degree + observer
+   1964_10c 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.
+
+ NOTE 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.
+
+ The -I b|w 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 -Ib. + If just display white level compensation is needed, use -Iw. If both are needed, use -Ibw or -Iwb.
+
+ The -Y R:rate + 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.
+
+ The -Y A + 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.
+
+ The -Y p + 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.
+
+ The -C "command" 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.
+
+ The -M "command" 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 "command.meas" + 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.
+
+ The -W n|h|x + parameter overrides the default serial communications flow control + setting. The value n turns + all flow control off, h + sets hardware handshaking, and x + sets Xon/Xoff handshaking. This commend may be useful in workaround + serial communications issues with some systems and cables.
+
+ The -D 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.
+
+ inoutfile + The final parameter on the command line is the base filename for the + .cal file and the optional ICC + profile. Normally this will be created (or an existing file will be + overwritten). If the -u + 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 -o flag.
+
+ NOTE that on an X11 system, + if the environment variable ARGYLL_IGNORE_XRANDR1_2 + 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.
+
+
+

Discussion and guide to display control + adjustment:

+
+ 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.
+
+ Almost all LCD displays lack a real contrast 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 contrast 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 contrast + control to neutral. The LCD brightness + 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 backlight + control as well as a brightness + 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 backlight + control in place of brightness + in the following adjustments.
+
+ 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.
+
+ On CRT based displays, the brightness + control generally adjusts the black level of the display (sometimes + called the offset), and as + a side effect, tends to change the maximum brightness too. A CRT contrast control generally + adjusts the maximum brightness (sometimes called gain) without affecting the + black level a great deal. On a CRT both the brightness and contrast controls will tend to + affect the shape or gamma of the display response curve.
+
+ 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.
+
+ 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 "white point selection" or R/G/B "gain" 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.
+
+ 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, dispcal + offers a menu of adjustment modes, so that the user can + interactively and iteratively adjust the display controls to meet + the desired targets.
+
+   1) Black level (CRT: Brightness)
+   2) White point (Color temperature, R,G,B, Gain/Contrast)
+   3) White level (CRT: Gain/Contrast, LCD: + Brightness/Backlight)
+   4) Black point (R,G,B, Offset/Brightness)
+   5) Check all
+   6) Measure and set ambient for viewing condition adjustment
+   7) Continue on to calibration
+   8) Exit
+
+ 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 -t -T or -w options, and on whether a + brightness target has been set using the -b option.
+
+
+ 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.
+
+   Adjust CRT brightness to get target level. + Press space when done.
+      Target + 0.60
+   / Current 0.68  + -
+
+ Once happy with the adjustment, press space to go back to the menu.
+
+
+ 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.
+
+    Adjust R,G & B gain to get + target x,y. Press space when done.
+      Target B 60.00, x 0.3451, y 0.3516
+   / Current B 60.05, x 0.3426, y 0.3506  DE  + 1.4  R+  G+  B--
+
+ 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 -T 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).
+
+ Adjust R,G & B gain to desired white point. + Press space when done.
+   Initial B 47.25, x + 0.3417, y 0.3456, CDT 5113 DE  6.9
+ \ Current B 47.38, x 0.3420, + y 0.3460  CDT 5104 DE  6.7  R-- G+  B-
+
+  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.
+
+
+ The third mode lets you adjust the brightness of white on the + display. If you set a target brightness using the -b + 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.
+
+    Adjust CRT Contrast or LCD + Brightness to get target level. Press space when done.
+      Target 60.00
+   / Current 59.96  +
+
+ 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:
+
+ Adjust CRT Contrast or LCD Brightness to desired + level. Press space when done.
+   Initial 47.32
+ / Current 47.54
+
+ Once happy with the adjustment, press space to go back to the menu.
+
+
+ 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. +
+
+   Adjust R,G & B offsets to get target x,y. + Press space when done.
+      Target B 0.60, x 0.3451, y 0.3516
+   \ Current B 0.62, x 0.2782, y 0.2331  DE  + 10.3  R+  G++ B-
+
+ 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.
+
+
+ The fifth selection checks on the overall settings.  If targets + have been set, it will be like:
+
+   Target Brightness = 50.00, Current = 47.44, + error = -5.1%
+   Target 50% Level  = 10.32, Current =  8.10, + error = -4.4%
+   Target Near Black =  0.47, Current =  0.68, + error =  0.4%
+   Target white = x 0.3458, y 0.3586, Current = x 0.3420, y + 0.3454, error =  7.55 DE
+   Target black = x 0.3458, y 0.3586, Current = x 0.2908, y + 0.2270, error = 29.69 DE
+
+ or if no targets are set:
+
+   Current Brightness = 46.28
+   Target 50% + Level  = 10.07, Current =  7.52, error = -5.5%
+   Target Near Black + =  0.46, Current =  0.46, error = -0.0%
+   Current white = x + 0.3439, y 0.3466, VCT 5098K DE  3.0
+   Target black = x + 0.3439, y 0.3466, Current = x 0.3093, y 0.2165, error = 30.30 DE
+
+ and will then go back to the menu.
+
+ The sixth selection 6) + allows the reading of you ambient lighting conditions if your + instrument supports such a mode. Doing so will enable the -a option to compensate for your + viewing conditions in the subsequent calibration. See -a.
+
+ Once  you're happy with the display set-up, you can either + proceed on to the rest of the calibration by selecting 7), or exit and re-start by + selecting 8). You might + want to re-start if you want to change the calibration targets.
+
+
+

Other caveats:

+ NOTE 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.
+
+ 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.
+
+ 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.
+
+ 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.
+
+ If communications break down with a USB connected instrument, you + may have to unplug it, and plug it in again to recover operation.
+
+ 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.
+
+
+
+
+
+ + -- cgit v1.2.3