@inproceedings{nshuti2015mobile,
title={Mobile Scanner and OCR ( A first step towards receipt to spreadsheet )},
author={Nshuti, Clement Ntwari},
year={2015}
}
Receipt detection | Receipt localization | Receipt normalization | Text line segmentation | Optical character recognition | Semantic analysis |
---|---|---|---|---|---|
❌ | ✔️ | ✔️ | ❌ | ❗ | ❌ |
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denoised using a gaussian blur
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sharpened
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a canny edge detector with [75, 200] as the thresholds
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extract the largest quadrilateral by approximating all closed regions in the output of the edge detector by quadrilaterals and keeping the largest from these.
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This quadrilateral is the extracted from the original (undenoised and unsharpened) image and warped into a straight rectangle.
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binarized using adaptive threshold
- Tesseract
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7 conditions tested:
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DARK.
The best conditions underwhich a picture can be taken is from the top with a dark background. This will be used as the baseline. Other configurations will be just a variation from this. We’ll either vary the background color, the camera orientation or the document quality.
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BRIGHT.
Pictures of the document from the top with a bright background
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NOISY
Pictures of the document with a background that has several small patterns.
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SIDE
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FRONT
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FOLDED
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CRINKLED
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