pnmgamma
Perform gamma correction on PNM images.
TLDR
Convert the image from BT.709 luminance to radiance or sRGB luminance
$ pnmgamma -[bt709tolinear|bt709tosrgb] [path/to/image.pnm] > [path/to/output.pnm]
Convert the image from radiance or sRGB luminance to BT.709 luminance
$ pnmgamma -[lineartobt709|srgbtobt709] [path/to/image.pnm] > [path/to/output.pnm]
Specify the gamma value used for the gamma transfer function
$ pnmgamma -gamma [value] [path/to/image.pnm] > [path/to/output.pnm]
Specify the gamma value used for the gamma transfer function per color component
$ pnmgamma -rgamma [value] -ggamma [value] -bgamma [value] [path/to/image.pnm] > [path/to/output.pnm]
