No takers huh? :( On Thursday, August 18, 2016 at 1:18:40 PM UTC-7, Luis Zertuche wrote: > > Hello Tesseract Gurus! > > I'm working on a pdf2text extraction for legal documents. I've done some > searches and found tips to improve quality, but I was wondering if someone > here can provide info beyond the basics. Image processing-wise I've been: > resizing to 600dpi, correcting for skew angle and [denoising with a median > filter, contrast stretching, dilating with a small structuring element and > otsu_thresholding] All those things improved the results only for a subset > of the documents and given how widely they vary in acquisition quality, > noise level and contrast, Ive realized the imaging pipeline is not one size > fits all. I'm considering creating parallel image processing pipelines and > do OCR on all of them and just pick the best, > > *1. Can anyone comment on what would be some good variations of an imaging > pipelines for 'high variance dirty-text' ? Or alternatively can anyone > think of an imaging pipeline that would cover a wider range of document > quality?* > > As far as tesseract parameters go. I've put together a small parameter > exploration loop evaluating iterations with a text-quality metric(M2, based > on number of dictionary words, using pyenchant), here is an example for the > linesize value parameter for a single document: > > +++For linesize value, 1.25, M2 value is 0.661157024793 > > +++For linesize value, 1.35, M2 value is 0.661157024793 > > +++For linesize value, 1.45, M2 value is 0.644628099174 > > +++For linesize value, 1.55, M2 value is 0.611111111111 > > +++For linesize value, 1.65, M2 value is 0.0 > > *+++For linesize value, 1.75, M2 value is 0.693693693694* > > +++For linesize value, 1.85, M2 value is 0.672413793103 > > +++For linesize value, 1.95, M2 value is 0.631578947368 > > +++For linesize value, 2.05, M2 value is 0.0 > > Here the best linsize value is 1.75 for that document, which yields good > results(the ). From this info, > > *2. Can anyone recommend what are some good parameters to do apply this > method with? Any other tips of combining parameters into something more > general o any other exploration tips? * > > Thanks for reading! Any other potentially useful tips or info would be > greatly appreciated, whether its on the image processing or on the > tesseract parameters. > > Best, Luis. > > >
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