pgmabel: 0 0 0 0
pgmbentley: 0 0 0 0
pgmdeshadow: 0 0 0 0
pgmenhance: 0 0 0 0
pgmhist: 0 0 0 0
pgmmedian: 0 0 0 0
pgmminkowski: 0 0 0 0
pgmtexture: 0 0 0 0
pgmtopbm -th : 0 0 0 0
pgmtoppm rgb:00/00/00 : 0 0 0 0
rawtopgm -headerskip 11 3 3 : 0 0 0 0