Computer Vision

This repository consists scripts for OCR (Optical Character Recognition) of white paper receipts. It includes Cropping (removing background), Improving Quality (if image is blurred), Binarization, Segmentation and Prediction.

Tools/Technologies Used:

Python, OpenCV, Ocropus and Tesseract.

Flowchart (How to use?)

References

1. Sharpening and Convolutions, OpenCv, https://www.pyimagesearch.com/2016/07/25/convolutions-with-opencv-and-python/
2. Gaussian Sharpening, Theory, http://biomedpharmajournal.org/vol7no2/image-sharpening-by-gaussian-and-butterworth-high-pass-filter/
3. https://en.wikipedia.org/wiki/Unsharp_masking#Digital_unsharp_masking
4. Gaussian Sharpening, OpenCV, https://stackoverflow.com/a/4993701
5. Laplacian Sharpening Theory, http://www.idlcoyote.com/ip_tips/sharpen.html.
6. Laplacian, https://stackoverflow.com/questions/39619222/laplacian-sharpening-grey-image-as-result
7. Modified Laplacian, https://stackoverflow.com/a/51138416
8. Lossy Problem, https://stackoverflow.com/a/52442741
9. Google Vision, https://www.quora.com/How-does-Google-Vision-API-works
10. 4-point transform algorithm, https://www.pyimagesearch.com/2014/08/25/4-point-opencv-getperspective-transform-example/
11. Document Scanner, https://www.pyimagesearch.com/2014/09/01/build-kick-ass-mobile-document-scanner-just-5-minutes/
12. Detect and Crop, https://www.quora.com/How-can-I-detect-an-object-from-static-image-and-crop-it-from-the-image-using-openCV
13. Crop a Contour, https://stackoverflow.com/questions/28759253/how-to-crop-the-internal-area-of-a-contour
14. Ocropus Part-A, http://www.danvk.org/2015/01/07/finding-blocks-of-text-in-an-image-using-python-opencv-and-numpy.html
15. Ocropus Part-B, https://www.danvk.org/2015/01/09/extracting-text-from-an-image-using-ocropus.html
16. Ocropus Part-C, http://www.danvk.org/2015/01/11/training-an-ocropus-ocr-model.html