ppmtoxpm
Convert a PPM image to an X11 version 3 pixmap.
TLDR
Convert a PPM image to a XPM image
$ ppmtoxpm [path/to/input_file.ppm] > [path/to/output_file.xpm]
Specify the prefix string in the output XPM image
$ ppmtoxpm -name [prefix_string] [path/to/input_file.ppm] > [path/to/output_file.xpm]
In the output XPM file, specify colors by their hexadecimal code instead of their name
$ ppmtoxpm -hexonly [path/to/input_file.ppm] > [path/to/output_file.xpm]
Use the specified PGM file as a transparency mask
$ ppmtoxpm -alphamask [path/to/alpha_file.pgm] [path/to/input_file.ppm] > [path/to/output_file.xpm]