ary.
      - All formats support 8 bpp grayscale (GIF must have a colormap).
      - All formats except GIF support rgb color.
      - All formats except PNM, JPEG, WEBP and JP2K support 8 bpp colormap.
      - PNG and PNM support 2 and 4 bpp images.
      - PNG supports 2 and 4 bpp colormap, and 16 bpp without colormap.
      - PNG, JPEG, TIFF, WEBP, JP2K and GIF support image compression;
        PNM and BMP do not.
      - WEBP supports rgb color and rgba.
      - JP2 supports 8 bpp grayscale, rgb color 