pnmhistmap(1) on Linux
The text 0d34d749a3f8, as Debian 13 (Trixie), Debian 12 (Bookworm) shipped it.
draw a histogram for a PGM or PPM file
Flags it lists
-
-black -
-blue -
-dots -
-green -
-height -
-lval -
-max -
-red -
-rval -
-verbose -
-white -
-width