Pgmramp User Manual(0)                   Pgmramp User Manual(0)



Table Of Contents


NAME
       pgmramp - generate a grayscale ramp


SYNOPSIS
       pgmramp -lr|-tb|-rectangle|-ellipse -maxval=maxval width
       height

       All options can be abbreviated to their shortest  unique
       prefix.   You may use two hyphens instead of one to des-
       ignate an option.  You may use either white space or  an
       equals sign between an option name and its value.


DESCRIPTION
       This program is part of Netpbm(1).

       Generates  a  graymap of the specified size containing a
       black-to-white ramp.  These ramps are useful for  multi-
       plying with other images, using the pnmarith tool.

       The  ramp  is linear in brightness, not intensity.  I.e.
       the gamma-corrected sample values in the PGM  rise  lin-
       early  with  distance  from the corner of the image.  If
       you want a ramp that is linear in light  intensity,  use
       pnmgamma with pgmramp.

       To  generate  a  simple ramp of all the values from 0 to
       maxval, and not necessarily a graphic  image,  use  pam-
       seq(1).


OPTIONS
       You must specify exactly one of the ramp type options.


       -lr    A left to right ramp.


       -tb    A top to bottom ramp.


       -rectangle
              An  outside-in  rectangular  ramp.   It  is black
              around the edges and white in the center.


       -ellipse
              An  outside-in  elliptical  ramp.   It  is  black
              around the edge and white in the center.


       -maxval=maxval
                   The maxval for the generated image.  Default
              is 255.

                   This option did not exist before June  2002.
              Before, the maxval was
                   always 255.





SEE ALSO
       pnmarith(1),   pnmgamma(1),   pamseq(1),  ppmrainbow(1),
       pgm(1)

AUTHOR
       Copyright (C) 1989 by Jef Poskanzer.



netpbm documentation      04 June 2002   Pgmramp User Manual(0)
