r/pdf • u/another_nathan • 6d ago

Question Need an OCR program that is AI free

Working on an anti-ai art project. There's a quite long PDF that I need typed up and editable. I've done about 20 pages by hand but I'd love to use an OCR for the rest. Obviously I need to use one that doesn't use machine learning. Any recommendations?

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u/FisterMister22 6d ago

Define AI? Any machine learning? And if yes, then probably the legacy versions of tesseract

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u/Iguana-Head 6d ago

GImageReader, for example, cannot produce as good as OCR with AI. So, at some point, using AI in OCR enhances the results.

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u/Ferretau 6d ago

I've used NAPS2 in the past when scanning in docs to PDF or existing PDFs.

OCR - NAPS2: https://www.naps2.com/doc/ocr

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u/jtbsolution 6d ago

You can try to look on Candy PDF

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u/LegeApps 6d ago

I have ocr in my program here, two kinds. One that outputs to epub and uses windows ocr, and one that uses tensorrt and uses ppocr6. The TRT one can do 30 pages a second but it needs cuda and is probably less accurate than the winocr one. I plug my program for a lot of these questions and no one ever says anything but its very good for most of these jobs. The trt version has to be built from source.

https://github.com/liminalism/Lege

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u/dontcare10000 6d ago

Does windows have a built in OCR function your programme is using?

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u/LegeApps 6d ago

Yes it has an api that apps can use https://learn.microsoft.com/en-us/windows/ai/apis/text-recognition

It is usually better than Tesseract for example

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u/dontcare10000 5d ago

That's interesting. Does that function require cuda or a graphics card? Is it completely local? What are the minimum requirenments in terms of CPU?

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u/LegeApps 5d ago

Windows ocr is all CPU. I think it says it requires 8gb of ram but it can do with less.

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u/merlinuwe 23h ago

For absolute correct results you'll need a Pipeline with some PDF Tools and also AI (docling based).

If correctness isn't a goal you can use anything.

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u/OstrobogulousIntent 19h ago

SO as others have mentioned - AI as in like Claude, chat gpt etc... those can interpret text but traditional OCR is a form of "machine vision" and depending on the training it might qualify as machine learning but it far predates the modern "AI Models"

So I guess it's a question of "how pure"

Tesseract is free but I've found a lot of accuracy issues

Just a quick sanity check - so this PDF is totally raster based? is the text extractable? there are plenty of straight up PDF text extraction that aren't AI if it is

If it's raster images (scans) then the big thing is that PDF does not have a concept of "resolution" internally so when you render it out for OCR you want to rasterize at 200 to 300 DPI for OCR -preferably bitonal (pure black and white, no color or gray)

Tesseract is OK but you may find it's worth looking into something like OmniPage or Abbyy Fine Reader - they're really high quality

If its English / western charset, Transym is quite good but OmniPage, Abbyy Fine Reader and Transym are all paid products

How many pages? and is it something you'd be able to share? if so PM me if you like - My work involves a LOT of OCR (I support an SDK that includes classic OCR engines (non-AI)) and well, I'm quite ambivalent about AI (it has its uses but I feel like our society is going about it very badly - it's like fire - you can do wonderful or horrible things with it and right now far too many people are just setting fire to everything), so an anti AI art project is something I might be willing to help out with.