Xerox scanners/photocopiers randomly alter numbers in scanned documents (2013)
The similar blocks technique used in JBIG2 is what's called the prediction step in many image codecs, or intra prediction in video. That specific technique is a perfectly fine idea so I've always wondered why more codecs don't use it - usually they don't let motion vectors point into the current frame.<p>But usually there's a step after it called residual coding, where you subtract the predicted image from the original and send the difference to make up for errors. Just leaving that out is, um, interesting.