optional_depends "ImageMagick" "--enable-imagemagick" "--disable-imagemagick" "for ImageMagick graphics support"
optional_depends "openexr"     "--enable-openexr"     "--disable-openexr"     "for EXR support"
optional_depends "tiff"        "--enable-tiff"        "--disable-tiff"        "for tiff graphics support"
optional_depends "netpbm"      "--enable-netpbm"      "--disable-netpbm"      "for netpbm graphics support"
optional_depends "gdal"        "--enable-gdal"        "--disable-gdal"        "for gdal support"
optional_depends "octave"      "--enable-octave"      "--disable-octave"      "for mathematical support"
