pnmpad(1) on Linux
The text 80db9fe1bff6, as Debian 13 (Trixie) shipped it.
add borders to a PNM image
Flags it lists
-
-black -
-bottom -
-color -
-detect-background -
-extend-edge -
-halign -
-height -
-left -
-mheight -
-mwidth -
-promote -
-reportonly -
-right -
-top -
-valign -
-verbose -
-white -
-width