NAME

       ra_gif - convert RADIANCE picture to Compuserve GIF

SYNOPSIS

       ra_gif  [ -b ][ -d ][ -c ncolors ][ -g gamma ][ -e +/-stops ][ -n sampfac ] input [ output
       ]

DESCRIPTION

       Ra_gif 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.   The  -b  option  converts  the
       image  to black and white.  The -d option turns off dithering.  The -c option allows fewer
       than 256 colors (and fewer than 8 bits per pixel).  The -g option specifies  the  exponent
       used  in  gamma  correction;  the  default  value  is 2.2.  An exponent of 1.0 turns gamma
       correction off.  The -e option specifies an exposure compensation in  f-stops  (powers  of
       two).  Only integer stops are allowed, for efficiency.  The -n option specifies a sampling
       factor for neural network color quantization.  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.

AUTHORS

       Greg Ward
       Paul Haeberli
       David Rowley
       Anthony Dekker provided the code for neural network color quantization

SEE ALSO

       pfilt(1),  ra_bmp(1),  ra_bn(1),  ra_ppm(1),  ra_pr(1),  ra_pr24(1),  ra_t8(1), ra_t16(1),
       ra_tiff(1), ximage(1)