Some years ago I heard about this German guy that found a mind boggling bug in Xerox scanners and the whole story how they tried to play it down is really insane. So definitely worth watching, unfort only with German audio: https://youtu.be/7FeqF1-Z1g0
But basically the JBIG2 image compression algorithm used in those scanners looked for certain repeating patterns, and incorrectly compressed certain portions of the image into “close enough” blocks of pixels. Unfortunately, that meant that scanned number data wasn’t guaranteed to be accurate, even when the decoded output clearly looked like a number with no distortion or noise.
Some years ago I heard about this German guy that found a mind boggling bug in Xerox scanners and the whole story how they tried to play it down is really insane. So definitely worth watching, unfort only with German audio: https://youtu.be/7FeqF1-Z1g0
He’s written up his findings in English, for anyone who prefers English over German or text over video.
But basically the JBIG2 image compression algorithm used in those scanners looked for certain repeating patterns, and incorrectly compressed certain portions of the image into “close enough” blocks of pixels. Unfortunately, that meant that scanned number data wasn’t guaranteed to be accurate, even when the decoded output clearly looked like a number with no distortion or noise.
It’s worth the full read.
I remember that video! For sure worth a watch