Section: User Commands (1)
Updated: 16 November 1993Index
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ppmshift - shift lines of a portable pixmap left or right by a random amount
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.
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
# 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.
Copyright (C) 1993 by Frank Neumann
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