pnmtopng(1) on Linux
The text c05a1bb610d8, as Debian 2.2 (Potato), Debian 2.1 (Slink) shipped it.
convert a portable anymap into a Portable Network Graphics file
Flags it lists
-
-alpha -
-background -
-compression -
-downscale -
-filter -
-force -
-gamma -
-hist -
-interlace -
-text -
-transparent -
-verbose -
-ztxt