and rgba.
   Use prog/ioformats_reg for a regression test on all formats, including
   thorough testing on TIFF.
   For more thorough testing on other formats, use:
      - prog/pngio_reg for PNG.
      - prog/gifio_reg for GIF
      - prog/webpio_reg for WEBP
      - prog/jp2kio_reg for JP2

   We provide generators for PS output, from all types of input images.
   The output can be either uncompressed or compressed with level 2
   (ccittg4 or dct) or level 3 (flate) encoding.  You have flexibility
   for 