pnmpaste
Paste a PNM image into another PNM image.
TLDR
Paste a PNM image into another PNM image at the specified coordinates
$ pnmpaste [x] [y] [path/to/image1.pnm] [path/to/image2.pnm] > [path/to/output.pnm]
Paste the image read from stdin into the specified image
$ [command] | pnmpaste [x] [y] [path/to/image.pnm] > [path/to/output.pnm]
Combine the overlapping pixels by the specified boolean operation, where white pixels represent true while black pixels represent false
$ pnmpaste -[and|nand|or|nor|xor|xnor] [x] [y] [path/to/image1.pnm] [path/to/image2.pnm] > [path/to/output.pnm]