NAME

       ppmshift - shift lines of a PPM image left or right by a random amount

SYNOPSIS

       ppmshift shift [ppmfile]

DESCRIPTION

       This program is part of Netpbm(1).

       ppmshift  reads a PPM image as input.  It shifts every row of image data to the left or right by a random
       amount, within a range of shift pixels.  The random distribution is uniform, centered at zero movement.

       The randomness in the image is limited before Netpbm 10.37 (December 2006) --  if  you  run  the  program
       twice in the same second, you may get identical output.

       This  is  an effect the author intended to use for MPEG tests.  Unfortunately, this program is not useful
       for that - it creates too random patterns to be used for animations.  Still, it  might  give  interesting
       results on still images.

OPTIONS

       There are no command line options defined specifically for ppmshift, but it recognizes the options common
       to all programs based on libnetpbm (See  Common Options .)

EXAMPLE

       Check  this out: Save your favorite 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
            pamcut -top=0 -width=800 -height=300 cs.ppm >upper.ppm

            #take the lower half, flip it upside down, dim it and distort it a little
            pamcut -top=300 -width=800 -height=300 cs.ppm | \
                pamflip -topbottom | \
                ppmdim 0.7 | \
                ppmshift 10 >lower.ppm

            #and concatenate the two pieces
            pamcat -topbottom 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(1), pamcut(1), pamflip(1), ppmdim(1), pamcat(1)

AUTHOR

       Copyright (C) 1993 by Frank Neumann

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/ppmshift.html

netpbm documentation                            20 November 2008                         Ppmshift User Manual(1)