pnmquantall

Run pnmquant on multiple files at once such that they share a common colormap. See also: pnmquant. More information: https://netpbm.sourceforge.net/doc/pnmquantall.html.

• Run pnmquant on multiple files with the specified parameters, overwriting the original files:

pnmquantall n_colors path/to/input1.pnm path/to/input2.pnm …

• Save the quantised 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 …