pnmscalefixed
Scale a PNM file quickly with possibly reduced quality. tldr-pages
On several platforms
Several platforms
Scale an image such that the result has the specified dimensions
pnmscalefixed -width width -height height path/to/input.pnm >path/to/output.pnmIdentifyScale an image such that the result has the specified width, keeping the aspect ratio
pnmscalefixed -width width path/to/input.pnm >path/to/output.pnmIdentifyScale an image such that its width and height is changed by the specified factors
pnmscalefixed -xscale x_factor -yscale y_factor path/to/input.pnm >path/to/output.pnmIdentify