pamcut
Cut out a rectangular region from a Netpbm image. tldr-pages
On several platforms
Several platforms
Discard the specified number of columns/rows on each side of the image
pamcut -cropleft value -cropright value -croptop value -cropbottom value path/to/image.ppm >path/to/output.ppmIdentifyKeep only the columns between the specified columns (inclusively)
pamcut -left value -right value path/to/image.ppm >path/to/output.ppmIdentifyFill missing areas with black pixels if the specified rectangle does not entirely lie within the input image
pamcut -top value -bottom value -pad path/to/image.ppm >path/to/output.ppmIdentify