This is the command pfsgamma that can be run in the OnWorks free hosting provider using one of our multiple free online workstations such as Ubuntu Online, Fedora Online, Windows online emulator or MAC OS online emulator
PROGRAM:
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 luminance.
--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.
Use pfsgamma online using onworks.net services
