xenial (1) ppmshift.1.gz

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)