tldr/pages/common/pnmgamma.md

pnmgamma

Perform gamma correction on PNM images. More information: https://netpbm.sourceforge.net/doc/pnmgamma.html.

• 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}}