QUANTIZE(9.1)                                       QUANTIZE(9.1)

          3to1, mcut, improve, quantize, dither - picture color

          fb/3to1 [ -e ] colormap [ input ]

          fb/mcut [ input ]

          fb/improve colormap [ input ]

          fb/quantize [ input ]

          fb/dither [ input ]

          3to1 approximates the full color (3 bytes per pixel) input
          picture file in one byte per pixel using the given colormap.
          If no input file is named, the picture is read from standard
          input.  The -e option suppresses the default error-diffusion

          Mcut writes a color map, suitable for use by 3to1 on its
          standard output.  The color map is computed using the
          median-cut algorithm and represents reasonably well, but not
          necessarily optimally, the colors of the input picture.

          Improve reads a color map and a picture and writes on stan-
          dard output a new color map that better represents the col-
          ors of the picture.  Multiple passes of improve may produce
          better and better color maps.

          Quantize is an rc script that packages all of the above to
          compress the full-color input image to one byte per pixel.

          Dither likewise compresses full-color images to one byte per
          pixel.  It uses a fixed color map that allows a speedy algo-
          rithm; quantize instead runs slower but gives better


     Page 1                       Plan 9             (printed 10/1/20)