Rediscovering The Past

Progress, as conceived by most people, consists in replacing older objects, techniques, or philosophies by newer, better, ones. Sometimes indeed the change is for the better, but sometimes it is just change for change—ever had an older device of some sort that was perfectly adequate for your usage, yet you still replaced it with a newer version with no net gain? Unfortunately, the same happens with ideas, especially with mathematics and computer science.

But there are lessons to be learnt from the past. I’m not talking about fables and cautionary tales; I’m talking about the huge body of science that was left behind, forgotten, superseded by modern techniques.

Getting Documents Back From JPEG Scans

We’re all looking for documentation, books, and papers. Sometimes we’re lucky, we find the pristine PDF, rendered fresh from a text processor or maybe LaTeX. Sometimes we’re not so lucky, the only thing we can find is a collection of JPEG images with high compression ratios.

Scans of text are not always easy to clean up, even when they’re well done to begin with, they may be compressed with JPEG using a (too) high compression ratio, leading to conspicuous artifacts. These artifacts must be cleaned-up before printing or binding together in a PDF.