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MCUT(1)                DragonFly General Commands Manual               MCUT(1)


NAME

       mcut - Quantize colors in an image using the median cut algorithm


SYNOPSIS

       mcut [ -n colors ] [ -d ] [ -o outfile ] infile


DESCRIPTION

       Mcut reads an RLE file and tries to choose the "best" subset of colors
       to represent the colors present in the original image.  A common use
       for this is to display a 24 bit image on a frame buffer with only eight
       bits per pixel using a 24 bit color map.  Mcut first quantizes
       intensity values from eight bits to five bits, and then chooses the
       colors from this space.

       Mcut runs in two passes; the first pass scans the image to find the
       color distributions, and the second pass maps the original colors into
       color map indices.  The output file has a color map containing the
       colors mcut has chosen.  Mcut also sets the picture comment
       "color_map_length" equal to the number of colors it has chosen.  The
       getx11 program (among others) will use this color map instead of
       dithering.


OPTIONS

       -n ncolors
              Limit the number of colors chosen to ncolors.  The default is
              200.

       -d     Uses Floyd/Steinberg dither to hide contouring.  Greatly
              improves images that have a small number of colors.

       infile The input will be read from this file.  If it is a multi-image
              file, each image will be quantized to its own colormap.  Piped
              input is not allowed.

       -o outfile
              If specified, output will be written to this file, otherwise it
              will go to stdout.


SEE ALSO

       getx11(1), rlequant(1), urt(1), RLE(5),
       "Color Image Quantization for Frame Buffer Display", by Paul Heckbert,
       Procedings of SIGGRAPH '82, July 1982, p. 297.


AUTHOR

       Robert Mecklenburg, John W. Peterson, University of Utah.


BUGS

       The initial quantization is hardwired to five bits.  This should be an
       option.

4th Berkeley Distribution      November 8, 1987                        MCUT(1)

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