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Ppmshift User Manual(0) 						  Ppmshift User Manual(0)

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.  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 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 anima-
       tions.  Still, it might give interesting results on still images.

EXAMPLE
       Check this out: Save your favourite model's picture from something like	alt.binaries.pic-
       tures.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
	    pnmcat -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) , pnmcat(1)

AUTHOR
       Copyright (C) 1993 by Frank Neumann

netpbm documentation			 20 November 2008		  Ppmshift User Manual(0)
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