converts from RADIANCE to Compuserve GIF color-mapped,
compressed image files.
In the default mode, a RADIANCE picture is converted to a
color-mapped GIF file of the same horizontal and vertical dimensions with
8-bits per pixel.
option converts the image to black and white.
option turns off dithering.
option allows fewer than 256 colors (and fewer than 8 bits per
option specifies the exponent used in gamma correction;
the default value is 2.2.
An exponent of 1.0 turns gamma correction off.
option specifies an exposure compensation in f-stops (powers of two).
Only integer stops are allowed, for efficiency.
option specifies a sampling factor for neural network color
This value should be between 1 and 80, where 1 takes the longest and
produces the best results in small areas of the image.
If no value is given, a faster median cut algorithm is used.
If the output file is missing, the standard output is used.
Anthony Dekker provided the code for neural network color quantization