ppmcolormask

Produce a mask of areas of a certain color in a PPM image. More information: https://netpbm.sourceforge.net/doc/ppmcolormask.html.

• Produce a mask of areas of a certain color in the specified PPM image:

ppmcolormask -color {{red,blue}} {{path/to/input.ppm}} > {{path/to/output.pbm}}