Gamma correction may be set by specifying a gamma correction value or by specifying a file that contains a gamma table.
The -g option will set the gamma table entries based on the gamma value specified. A gamma value of 2.22 represents linear gamma correction and matches the fixed value on the Elite3D products. This value is a per-screen value and therefore all gamma corrected or linear visuals will use this value.
The -gfile option will set the gamma table entries explicitly from a file containing three columns of 256 integers ranging from 0 to 255. The format is three integers separated by a newline character. Each line contains the RGB value to be put in the table for that entry. This value is a per-screen value and therefore all gamma-corrected or linear visuals will use this value.