HSLCOM is a small utility program which combines three grayscale image maps
in GIF, POT, PGM, or POV-Ray style TGA (NOT standard TGA) formats, into a
single standard 24-bit TGA file.  This is one way to get "truecolor" fractal
images; you'd generate three GIF or POT files in Fractint and then combine
them with HSLCOM. The three input files are taken to be hue, saturation, and
luminosity (intensity or brightness) values for the respective pixels. You
can specify the subranges of each H,S,L on the command line as optional
parameters (type HSLCOM with no options for usage instruction). An example:

 hslcom frac1.gif frac2.gif frac3.gif 0.0 1.0  0.0 1.0    0.0 1.0
                                      hue      saturation luminosity

This gives you an output TGA file comprising the full range of hue, sat, and
luminosity values (each ranges from 0..1).  Or another example,

 hslcom f1.pot f2.pot f3.pot 0.1 0.3 0.6 1.0 0.4 0.8

Which gives you a medium lightness (.4-.8), more saturated (.6-1) reddish
(.1-.3) image.  The ranges are described as follows:

  HUE: 0.0=Red    0.4=Yellow-Green   0.8=Blue   etc. etc.
  SAT: 0.0=Grey   1.0=fully saturated
  LUM: 0.0=Black  1.0=White

IMPORTANT: hslcom requires GO32.EXE (the DJGPP 32-bit DOS extender) to be 
present in in your search path. It should be available in the same place 
you got hslcom. You can get the entire DJGPP compiler environment, free,
for FTP from many places including ftp://oak.oakland.edu/ .

Source code for hslcom.c is included in the "hutil" collection, at
  
  http://jump.stanford.edu:8080/gforge/hutil01d.tar.gz


-John Beale <beale@jump.stanford.edu>  12/6/95