icontopbm
converts a Sun icon file to PBM format
TLDR
Convert icon to PBM
$ icontopbm [file.icon] > [output.pbm]
Convert from stdin$ cat [file.icon] | icontopbm > [output.pbm]
SYNOPSIS
icontopbm [iconfile]
DESCRIPTION
icontopbm converts a Sun icon file to PBM (Portable Bitmap) format. Part of the Netpbm package of graphics manipulation tools. Reads from stdin if no file is specified.