NAME

       ppmbrighten - change an images Saturation and Value from an HSV map

SYNOPSIS

       ppmbrighten [-n] [-s <+- saturation>] [-v <+- value>] <ppmfile>

DESCRIPTION

       Reads  a  portable  pixmap  as  input.  Converts the image from RGB space to HSV space and
       changes the Value by <+- value> as a percentage.  Likewise with the Saturation.   Doubling
       the Value would involve

       ppmbrighten -v 100

       to add 100 percent to the Value.

       The 'n' option normalizes the Value to exist between 0 and 1 (normalized).

SEE ALSO

       pgmnorm(1), ppm(5)

AUTHOR

       Copyright (C) 1990 by Brian Moffet Copyright (C) 1989 by Jef Poskanzer.

       Permission  to  use,  copy, modify, and distribute this software and its documentation for
       any purpose and without fee is hereby granted, provided that the  above  copyright  notice
       appear in all copies and that both that copyright notice and this permission notice appear
       in supporting documentation.  This software is provided "as is" without express or implied
       warranty.

NOTES

       This program does not change the number of colors.

                                           20 Nov 1990                             ppmbrighten(1)