ppmshift

ppmshift(1)                 General Commands Manual                ppmshift(1)

NAME
       ppmshift  -  shift lines of a portable pixmap left or right by a random
       amount

SYNOPSIS
       ppmshift shift [ppmfile]

DESCRIPTION
       Reads a portable pixmap as input. Shifts every row of image data to the
       left  or right by a certain amount. The 'shift' parameter determines by
       how many pixels a row is to be shifted at most.

       Another one of those effects I intended to use for MPEG tests.   Unfor-
       tunately,  this  program  will not help me here - it creates too random
       patterns to be used for animations. Still, it  might  give  interesting
       results on still images.

EXAMPLE
       Check this out: Save your favourite model's picture from something like
       alt.binaries.pictures.supermodels  (ok,  or  from  any  other   picture
       source), convert it to ppm, and process it e.g. like this, assuming the
       picture is 800x600 pixels:
         # take the upper half, and leave it like it is
         pnmcut 0 0 800 300 cs.ppm >upper.ppm

         # take the lower half, flip it upside down, dim it and distort it a little
         pnmcut 0 300 800 300 cs.ppm | pnmflip -tb | ppmdim 0.7 |
            ppmshift 10 >lower.ppm

         # and concatenate the two pieces
         pnmcat -tb upper.ppm lower.ppm >newpic.ppm
       The resulting picture looks like the image being reflected on  a  water
       surface with slight ripples.

SEE ALSO
       ppm(5), pnmcut(1), pnmflip(1), ppmdim(1), pnmcat(1)

AUTHOR
       Copyright (C) 1993 by Frank Neumann

                               16 November 1993                    ppmshift(1)