chickadee » leptonic » pix-threshold-to-4bpp

pix-threshold-to-4bppprocedure
  • in - PPIX - 8bpp
  • in - NLEVELS - 2..16 equally spaced levels in output
  • in - CMAP? - 0/1
  • returns: dithered 4bpp ppix or #f on error.