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pfsgamma(1) [debian man page]

pfsgamma(1)						      General Commands Manual						       pfsgamma(1)

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: 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 ( pfsgamma(1)

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pfsoutppm(1)						      General Commands Manual						      pfsoutppm(1)

pfsoutppm, pfsouttiff, pfsoutrgbe, pfsoutexr - Write images or frames in one of the several formats SYNOPSIS
pfsoutppm (<file> [--srgb] [--frames <range>]) [<file>...] pfsouttiff (<file> [--srgb] [--frames <range>]) [<file>...] pfsoutrgbe (<file> [--frames <range>]) [<file>...] pfsoutexr (<file> [--frames <range>]) [<file>...] DESCRIPTION
This command can be used to write pfs frames piped to standard input in one of the several recognized formats. See the manual page of pfs- inppm to get a list of available formats. To write images to standard output use a single dash '-' instead of filename. Each file name can contain a %d pattern, which is substituted with frame numbers. The pattern has the same syntax as C printf command. For example, you can use %04d to make the frame number four digit with proceedings zeros. You can select the frames using the following options (the options must be always given after the file name): --frames <range> Range is given in mathlab / octave format: startframe:step:endframe Frame numbers start with startframe (default 0), are increased by step (default 1) and stop at endframe You can skip one of those values, for example 1:100 for frames 1,2,...,100 and 0:2: for frame 0,2,4,... up to the last file that exists. --srgb, -s Apply the sRGB non-linearity (approximately 2.2 gamma) before writing a file. This can be used instead of using pfsgamma -g 2.2 to store the result of some tone-mapping operators. The option will compress contrast to make sure that tone values are properly shown on a display. It should be only used with linearized (not gamma corrected) images that are normalized to the 0-1 range. --bit-depth <val>, -b <val> Enforce bit-depth (per color channel). The allowed values are from 8 to 32. If not specified, the bit depth from the pfs stream ('BITDEPTH' tag) will be used instead. If the 'BITDEPTH' tag is missing, the ImageMagick default value will be used (usually 16). The bit depth of actually stored file may be lower of that specified, if the file format does not support higher bit depths. EXAMPLES
pfsin memorial.tiff | pfsoutrgbe memorial.hdr Converts from one HDR format to another pfsin test.jpg | pfsout test.png Convert from one image format to another. pfsin --linear test.jpg | pfsout --srgb test.png The same as above, but apply inverse gamma correction after reading an image (--linear) and then apply gamma correction before writ- ing an image (--srgb). SEE ALSO
pfsout(1) pfsinppm(1) BUGS
Please report bugs and comments on implementation to the discussion group pfsoutppm(1)
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