PBM handles the following formats:

    Sun icon file				reading	writing
    Sun raster file				reading	writing
    X10 and X11 bitmap file			reading	writing
    MacPaint					reading	writing
    CMU window manager format			reading	writing
    MGR format					reading	writing
    Group 3 FAX					reading	writing
    X11 window dump file			reading	writing
    X10 window dump file			reading
    Xerox doodle brushes			reading
    GEM .img format				reading
    PC paintbrush (.pcx) format			reading
    PICT					reading
    ASCII graphics					writing
    HP LaserJet format					writing
    GraphOn graphics					writing
    BBN BitGraph graphics				writing
    Printronix format					writing

PGM handles the following formats:

    TIFF					reading
    Usenix FaceSaver file			reading
    HIPS					reading
    FITS					reading	writing
    PostScript "image" data			reading
    raw grayscale bytes				reading
    Encapsulated PostScript				writing

PPM handles the following formats:

    color Sun raster file			reading	writing
    GIF						reading	writing
    Amiga IFF ILBM				reading	writing
    color X11 window dump file			reading	writing
    color X10 window dump file			reading
    MTV ray-tracer output			reading
    QRT ray-tracer output			reading
    TrueVision Targa file			reading
    Img-whatnot file				reading
    color Encapsulated PostScript			writing