This program is part of Netpbm.
ppmtoapplevol reads a PPM image as input and produces an Apple volume label image as output.
EFI-based Apple systems use a simple image format to provide textual labels for devices. This program generates that format.
The input image must be exactly 12 rows tall. Use pamfile to see how tall your image is and pamscale or pamcut to make it 12 rows if it isn't.
Netpbm does not have a converter for the other direction.
ppmtoapplevol was new in Netpbm 10.54 (March 2011).