xbmtopbm
Convert X11 bitmap to PBM format
TLDR
Convert XBM to PBM
$ xbmtopbm [input.xbm] > [output.pbm]
SYNOPSIS
xbmtopbm [file]
DESCRIPTION
xbmtopbm converts X11 bitmap format (.xbm) to PBM. X bitmaps are C source files; this extracts the image data. Part of Netpbm toolkit.