xgamma(1) [debian man page]
xgamma(1) General Commands Manual xgamma(1) NAME
xgamma - Alter a monitor's gamma correction through the X server SYNOPSIS
xgamma [-display display] [-screen screen] [-quiet] [-gamma f.f | [[-rgamma f.f] [-ggamma f.f] [-bgamma f.f]]] DESCRIPTION
xgamma allows X users to query and alter the gamma correction of a monitor via the X video mode extension (XFree86-VidModeExtension). Note that the xgamma utility is obsolete and deficient, xrandr should be used with drivers that support the XRandr extension. If no value for the gamma correction is given via the -gamma or -rgamma/-ggamma/-bgamma options, xgamma prints the current gamma correction of the display. OPTIONS
-display display This argument allows you to specify the server to connect to; see X(7). -screen screen When multiple displays are configured as a single logical display, this option allows you to select the screen you wish to change. -quiet Silence the normal output of xgamma -help Print out the `Usage:' command syntax summary. -gamma f.f The gamma correction can either be defined as a single value, or separately for the red, green and blue components. This argument specifies the gamma correction as a single value. -rgamma f.f This argument specifies the red component of the gamma correction. -ggamma f.f This argument specifies the green component of the gamma correction. -bgamma f.f This argument specifies the blue component of the gamma correction. ENVIRONMENT
DISPLAY To get default host and display number. BUGS
This client changes the internal values of the gamma correction for the Xserver. Whether or not these values are respected depends on the video drivers. The gamma values are passed to the Xserver with 3 decimal places of accuracy. SEE ALSO
xvidtune(1), xrandr(1) AUTHORS
Kaleb S. Keithley, X Consortium. David Dawes, David Bateman X Version 11 xgamma 1.0.5 xgamma(1)
Check Out this Related Man Page
pfsgamma(1) General Commands Manual pfsgamma(1) NAME
pfsgamma - Apply gamma correction to color or gray-scale images SYNOPSIS
pfsgamma [--gamma <gamma> | --inverse-gamma <inv-gamma>] [--mul <multiplier>] DESCRIPTION
Use this command to gamma correct a stream of pfs images. Gamma correction is equivalent to raising value of R, G and B (or Y for gray- scale images) channels to 1/gamma power. More information on gamma correction can be found at: http://www.poynton.com/notes/colour_and_gamma/GammaFAQ.html This command can work on color images, in which case XYZ channels are transformed to RGB space, then they are gamma corrected before they are converted back to XYZ. For gray-scale images (only Y channel and XZ missing) gamma correction is applied only to Y channel. Data can be multiplied by an optional multiplier before gamma correction. Note: gamma correction will set the 'LUMINANCE' tag to 'DISPLAY' thus cancelling any sRGB correction when saving to LDR files (like PPM, TIFF). This will also cause a warning message when saving to HDR files, because the intensities after gamma correction are not linearly related to luminance any more. OPTIONS
--gamma <gamma>, -g <gamma> Perform gamma correction (input^(1/gamma)). This can be used to convert images from relative luminance or radiance to pixel values. Default value: 1.0 --inverse-gamma <inv-gamma>, -i <inv-gamma> Perform inverse gamma correction (input^(gamma)). This can be used to convert images from pixel values to relative radiance or lumi- nance. --mul <mul>, -m <mul> Multiply data by this value before gamma correction. Default value: 1 EXAMPLES
pfsin memorial.hdr | pfsgamma -g 1.8 -m 10 | pfsout memorial_gc.ppm Multiply memorial image by 10, gamma correct it and save to memorial_gc.ppm. SEE ALSO
pfsin(1) pfsout(1) pfsdisplayfunction(1) BUGS
Please report bugs and comments to the pfstools discussion group (http://groups.google.com/group/pfstools). pfsgamma(1)