4 ms·
You can train Tesseract to recognize Handwriting[1], but the first and most important step would be the preprocessing of your documents. I would recommend to st
by sandreas 3y ago
You can train Tesseract to recognize Handwriting[1], but the first and most important step would be the preprocessing of your documents. I would recommend to start with a local adaptive thresholding algorithm[2] like Sauvola for binarization. The preprocessing steps would be[3]
1) Binarization
2) Skew Correction
3) Noise Removal
4) Thinning and Skeletonization
Probably you are facing "Sütterlin"[4], which differs quite a bit from modern german handwriting.
In your case (only 200 pages) it might be easier to use template matching[5] to identify similar characters and just "transliterate" matches into modern printed letters (like an overlay over the original text). This way you would have a quick solution while still being accurate enough to just read it.
[1]: https://tesseract-ocr.github.io/tessdoc/#training-for-tesseract-5 https://tesseract-ocr.github.io/tessdoc/#training-for-tesser...
[2]: https://brandonmpetty.github.io/Doxa/WebAssembly/ https://brandonmpetty.github.io/Doxa/WebAssembly/
[3]: https://towardsdatascience.com/pre-processing-in-ocr-fc231c6035a7 https://towardsdatascience.com/pre-processing-in-ocr-fc231c6...
[4]: https://de.wikipedia.org/wiki/S%C3%BCtterlinschrift https://de.wikipedia.org/wiki/S%C3%BCtterlinschrift
[5]: https://docs.opencv.org/3.4/d4/dc6/tutorial_py_template_matching.html https://docs.opencv.org/3.4/d4/dc6/tutorial_py_template_matc...
- nadermx 3y agoThis is great, I also did find this https://github.com/IgorMeloS/OCR/blob/main/7%20-%20template-matching/template-matching.ipynb https://github.com/IgorMeloS/OCR/blob/main/7%20-%20template-... which is part of this https://github.com/IgorMeloS/OCR https://github.com/IgorMeloS/OCR could be useful for this as well.
- throwup238 3y agoThe letters from [4] remind me of modern Russian cursive which has some similarly interesting changes to some letters to make them faster to write. I wonder if there's any research on Russian cursive OCR that could help
- gumby 3y ago> Probably you are facing "Sütterlin"[4], which differs quite a bit from modern german handwriting. My mother in law (and her mother) wrote everything in Sütterlin and I found it rapidly became pretty easy to read, though that also could be because I only encountered it from a small number of hands. OTOH I find older Handschrift and Fraktur print (we have a bunch of old books in that) basically illegible.
- aaron695 3y ago[dead]