ref: b0a059537147237e868b4a8f07922ae8a349e55c
dir: /sys/src/cmd/postscript/postdmd/README/
DMD bitmap to PostScript translator. Much of the code came from abm, which was written by Guy Riddle. By default 6 byte patterns are used to encode the output bitmap. Use the -b option to change the pattern size. Bitmaps are unpacked one scanline at a time and re-encoded in a format that looks like, bytes patterns count where bytes and count are decimal integers and patterns is a series of hex digits. Bytes is the number of bytes represented by the hex pattern, and count is the number of additional times the pattern should be repeated. For example, 2 FFFF 4 5 FFFFFFFFFF 1 10 FFFFFFFFFFFFFFFFFFFF 0 all represent 10 consecutive bytes of ones. Scanlines are terminated by a 0 on a line by itself.