man > pamgradient(1)

Pamgradient User Manual(1)             General Commands Manual            Pamgradient User Manual(1)

NAME
       pamgradient - create a four-corner gradient PAM 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 sep‐
       arate an option name from its value.



DESCRIPTION
       This program is part of Netpbm(1).

       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 ]8;;libnetpbm_image.html#colorname\argument of the pnm_parsecolor() library routine]8;;\ .

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


OPTIONS
       In  addition  to  the options common to all programs based on libnetpbm (most notably -quiet,
       see ]8;;index.html#commonoptions\ Common Options]8;;\ ), pamgradient recognizes the following command line option:



       -maxval=maxval


              maxval of the generated image.  (See PAM(1) and PNM(1) specifications).



SEE ALSO
       pamgradient(1), ppmmake(1), ppmrainbow(1), pgmramp(1), ppmpat(1), pam(1), pnm(1)


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 solid sur‐
       face.

       This effect is created by the integer arithmetic used for the interpolation of the color val‐
       ues,  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.

DOCUMENT SOURCE
       This manual page was generated by the Netpbm tool 'makeman' from  HTML  source.   The  master
       documentation is at

              http://netpbm.sourceforge.net/doc/pamgradient.html

netpbm documentation                       21 October 2005                Pamgradient User Manual(1)