NAME
      rgb_to_bw - convert a color scanline to black
      and white.

 SYNOPSIS
      #include <rle.h>

      void rgb_to_bw( red, green, blue, bw, length );
      rle_pixel * red, * green, * blue, *bw;
      int length;

 DESCRIPTION
      rgb_to_bw converts red/green/blue color
      information to black and white using the NTSC
      Y transform:
      Y = 0.30 * R + 0.59 * G + 0.11 * B  .  The
      arguments point to scanlines with length
      bytes in each.  bw may be identical to one of
      red, green, or blue.

 SEE ALSO
      tobw(1), librle(3), RLE(5).

 AUTHOR
      Spencer W. Thomas
      University of Utah
























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