minix man page for 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.  Unfortunately, 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)