PPMSHIFT(1)

💅 ppmshift — the Netpbm glow-up you didn't know you needed

okay bestie, this is a page from the Ppmshift User Manual, section 1 of the General Commands Manual, and it's about to shift your whole world. literally. sideways. randomly. 🦋

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✨ NAME ✨

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

✨ SYNOPSIS ✨

ppmshift shift [ppmfile]

✨ DESCRIPTION ✨

so this program is part of Netpbm(1), iconic family, no notes. 🫶

ppmshift reads a PPM image as input, and then it does the thing: it shifts every row of image data to the left or to the right by a random amount, somewhere within a range of shift pixels. the random distribution is uniform and it's centered at zero movement — so like, on average, nobody's going anywhere, but every individual row is out here making choices. 💀

ngl, 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. same second, same vibe. 🙈

the tea: this is an effect the author intended to use for MPEG tests. unfortunately, that did not work out — it creates too random patterns to be used for animations. 😭 but lowkey? it might still give interesting results on still images. main character energy on a static pic. ✨

✨ OPTIONS ✨

there are no command line options defined specifically for ppmshift, bestie. but it does recognize the options common to all programs based on libnetpbm — see Common Options. (iykyk.) 👑

✨ 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

and the resulting picture looks like the image being reflected on a water surface with slight ripples. 🌊 absolutely ate, fr fr. 🔥

✨ 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

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and that's the whole page, bestie 💖 this one came from the netpbm documentation, dated 20 November 2008, and it's giving very much "Ppmshift User Manual(1)" in the footer. slay, bye 🎀✨🌸