pamgradient

                                  pamgradient

   Updated: 21 October 2005
   Table Of Contents

NAME

   pamgradient - create a four-corner gradient PAM or PNM image

SYNOPSIS

   pamgradient [-maxval=maxval] color-tl color-tr color-bl color-
br
   width height

   Minimum unique abbreviation of option is acceptable.  You  may
use double
   hyphens  instead  of  single hyphen to denote options. You may
use white space
   in place of the equals sign to separate an  option  name  from
its value.

DESCRIPTION

   This program is part of Netpbm.

   pamgradient creates an image of the specified dimensions width
by height
   which contains a smooth, two-dimensional gradient between  the
specified
   colors of the four corners (from top left to bottom right).

   Specify  the  colors  as  described  for  the  argument of the
ppm_parsecolor()
   library routine.

   If all four colors are  gray  values,  pamgradient  creates  a
grayscale image
   (PAM  tuple type GRAYSCALE). Otherwise, it creates a color im-
age (PAM tuple
   type RGB).

OPTIONS

   -maxval=maxval
          maxval of the generated image. (See PAM and PNM  speci-
fications).

SEE ALSO

   ppmmake, ppmrainbow, pgmramp, ppmpat, pam, pnm

NOTE

   Only  the  top  left corner of the generated image has exactly
the specified
   color. The color of the top right corner is a bit  shifted  to
the left, the
   bottom  left corner a bit up, and the bottom right corner left
and up. This
   ensures nice transitions when combining adjacent (very narrow)
gradients,
   and doesn’t play a role when the gradient butts against a sol-
id surface.

   This effect is created by the integer arithmetic used for  the
interpolation
   of  the  color  values, and since it doesn’t make a difference
for all
   practical purposes I might as well sell it as a feature.

HISTORY

   pamgradient was new in Netpbm 10.31 (December 2005).

AUTHOR

   pamgradient was written by Daniel Haude in October 2005.
     _________________________________________________________________

Table Of Contents

     * NAME
     * SYNOPSIS
     * DESCRIPTION
     * OPTIONS
     * SEE ALSO
     * NOTE
     * HISTORY
     * AUTHOR