Usage of Hough Transform for Expiry Date Extraction via Optical Character Recognition

In this article we evaluate the impact of using two image pre-processing approaches with the objective of aiding an Optical Character Recognition (OCR) software in correctly retrieving an expiry date from an image of a product containing it. In particular, we analyze the impact of finding the rotation angle of an image using the Hough transform and the impact of image binarization using adaptive Gaussian threshold. We attempt to further increase OCR accuracy through a sliding window approach. Our results show that applying the Hough transform noticeably improves OCR performance with minimal impact on the execution time.