pnmquantall
Run pnmquant on multiple files at once such that they share a common colormap. tldr-pages
On several platforms
Several platforms
Run pnmquant on multiple files with the specified parameters, overwriting the original files
pnmquantall n_colors path/to/input1.pnm path/to/input2.pnm ...IdentifySave the quantized images to files named the same as the input files, but with the specified extension appended
pnmquantall -ext extension n_colors path/to/input1.pnm path/to/input2.pnm ...Identify