pamcut
Cut out a rectangular region from a Netpbm image.
TLDR
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.ppm]
Keep only the columns between the specified columns (inclusively)
$ pamcut -left [value] -right [value] [path/to/image.ppm] > [path/to/output.ppm]
Fill 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.ppm]
