Remember when office walls were festooned with grubby, wonkily photocopied slogans, bad attempts at Snoopy cartoons, and all manner of xerox-worn paperwork? Something like this:
With everything being digital, and e-mailed the world over without degradation, I became nostalgic for the old analogue days. So I decided to emulate the squint, black-edged, mottled, heavily-thresholded imagery with the NetPBM toolkit and a shell script. You can download it here: pnmcopier – emulate a badly-photocopied document to stdout. It should work on most Unix machines. It does require that your shells sets $RANDOM, which might make it a bit bash-specific.
It works best with a fairly high resolution image. Be advised it’s a processor hog; it has to rotate, smooth and merge very large images. To compound the effect, pipe the output into pnmcopier, perhaps several times. I don’t quite have the parameters right, but it gives the desired level of grubbiness. Sorry I couldn’t reproduce coffee stains, staple marks, old tape ghosts or random doodles.
Do what you will with it, but harm none.