I often end up with PDFs of old math papers and books that are not searchable and cannot be highlighted (basically, they display like images). One way to make them searchable is to apply optical character recognition (OCR). There are several free OCR engines online, but they often limit the size of a file you can upload (in practice, number of pages must be less than 30). Alternatively, you can buy Adobe Pro, but that's a lot more than you need if you only need to OCR. Other programs tend to output text as Word files, and tend to ruin mathematical equations. My question is:
Does anyone know of any OCR programs that work well for mathematical documents?
I have a PC, a Mac, and a Linux machine (this is what happens when you teach CS) so platform doesn't matter.
I feel like this question would be important to math researchers, but questions in the past on technology have met mixed support. Since my main goal is to get a good OCR program (even if it's not free) that works for math papers, I figured I'd ask here. If people think it's appropriate for MO, I'm happy to migrate.