spectro/dispwin

Summary

This utility has a couple of different functions. When given as a file argument an ICC profile containing vcgt "gamma" curves, or an Argyll video calibration .cal file, it will load that calibration into the chosen display. By default it displays a test window the same as that used by dispcal and dispread, to test this functionality. It can also be used to test the ability to load video card LUT curves to each display.

Usage

dispwin [options] [calfile]
 -v                   Verbose mode
 -display displayname [X11 only] Choose X11 display name
 -d n                 Choose the display from the following list (default 1)
 -p ho,vo,ss          Position test window and scale it
                      ho,vi: 0.0 = left/top, 0.5 = center, 1.0 = right/bottom etc.
                      ss: 0.5 = half, 1.0 = normal, 2.0 = double etc.
 -i                   Run forever with random values
 -r                   Test just RAMDAC (video LUT loading)

 
calfile              Name of ICC profile or Argyll .cal file to load into the display LUTs.

Comments

The -v flag makes the program more verbose..

When running on a UNIX based system that used the X11 Windowing System, dispwin will by default use the $DISPLAY environment variable to determine which 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 dispwin 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 -display parameter.

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. 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. 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. Note that the ho,vo,ss 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 .

By default dispwin will put a test window on the selected display, and display six test colors, before darkening  then brightening the screen by loading video LUT values, restore the original values and then exit.

If the -i flag is set, then dispwin will display random test colors forever.

If the -r flag is set, then dispwin will test the loading of video LUT values by first darkening, then lightening the screen, before exiting.

The final optional parameter on the command line is the name of an ICC profile that contains a display LUT vcgt tag, or an Argyll .cal format display calibration. If this parameter is provided, then the selected display will be loaded with the given calibration. This is useful in initializing a system to the current calibration on system startup.