alt Hacker NewsI'd like to hear more about what works in OCR of dot-matrix fonts.
I've been able to OCR letter-quality printer output to 97% (mostly Os and Xs problems).
But it seems that machine-learning text-recognition is also now biased to reject computer code because it doesn't look like human language.
Replies
embedding-shape • today at 10:33 AM
Boring reply perhaps, but I've had wild success with adding even a tiny LLM afterwards to do "fixups" over OCRd text, works great for the typical O/0 issues and similar, just pass it the scrambled OCRd text together with the text around it, and even dumb and tiny 7b models running on CPU do a pretty fine job.
bob778 • today at 10:45 AM
ABBYY has a specific module for dot matrix printouts so I’m surprised it was a struggle for them but every document is different
There's a writeup here from one of the people on the team about the work it took to go from the listings to source code. http://cini.classiccmp.org/recoveryblog.htm
> With less-than-satisfactory OCR output, I resorted to a process I used many years ago when converting scans made of old Commodore ROM dumps printed on a Commodore 1515 dot-matrix printer. The process relies on the ASCII OCR output having the same repetitive errors. "B" and "8", "S" and "5" are good examples, as are "l" and "1", and "O" and "0". There are many other similar single-character errors and, when working with x86 code, there are similar errors with instructions like "MOV". This process naturally works better if the output file is monolithic rather than single-page OCR conversions because you can do substitutions across the entire converted printout and not 75 separate files.
> The next formatting hassle was the spacing. This required repetitive substitutions of a descending numbers of spaces to tabs (i.e., replace 8 spaces with a tab, 7, 6, etc.). Then if you want to return it to fixed spaces (which is likely how the original printer printed it -- spaces and not vertical tabs), you can. For pure re-creation work, spaces produce absolute column formatting while tabs can move around depending on the program displaying the file.
> Once you run thought the 15 or so common global substitutions and tab conversion, it's a lot easier to work with the file to fix formatting and perform other cleanup. This is then followed by a line-by-line comparison against the original printouts. Overall I'd say the conversion output quality with this method is very good.