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 | 1 | initial version |
The Perona-Malik anisothropic diffusion (from the OpenCV extended image processing module) is used a lot for photo denoising. It accentuates linear structures (like the lines), so it will keep the lines from the fonts.
If you want to go further, here's the thesis of Romulus Terebes that proposes a variant of this method for old document restauration: http://www.theses.fr/2004BOR12819
If you need this step as a preprocessing before OCR, you could use the grayscale image directly with a DNN. A simple network, like the LeNet, already gives excellent results for character recognition even for noisy data.
| | 2 | No.2 Revision |
The Perona-Malik anisothropic diffusion (from the OpenCV extended image processing module) is used a lot for photo denoising. It accentuates linear structures (like the lines), so it will keep the lines from the fonts.
If you want to go further, here's the thesis of Olivier Lavialle and Romulus Terebes that proposes a variant of this worked on applying the Perona-Malik method for on linear structure enhancement in old document restauration: http://www.theses.fr/2004BOR12819documents: Habilitation (see results on page 27) and Thesis.
If you need this step as a preprocessing before OCR, you could use the grayscale image directly with a DNN. A simple network, like the LeNet, already gives excellent results for character recognition even for noisy data.
