An end-to-end Optical Character Recognition approach for ultra-low-resolution printed text images
Some historical and more recent printed documents have been scanned or stored at very low resolutions, such as 60 dpi. Though such scans are relatively easy for humans to read, they still present significant challenges for optical character recognition (OCR) systems. The current state-of-the art is to use super-resolution to reconstruct an approximation of the original high-resolution image and to feed this into a standard OCR system. Our novel end-to-end method bypasses the super-resolution step and produces better OCR results. This approach is inspired from our understanding of the human visual system, and builds on established neural networks for performing OCR. Our experiments have shown that it is possible to perform OCR on 60 dpi scanned images of English text, which is a significantly lower resolution than the state-of-the-art, and we achieved a mean character level accuracy (CLA) of 99.7 of 60 dpi text in a wide range of fonts. For 75 dpi images, the mean CLA was 99.9 and data (including a set of low-resolution images with their ground truths) publicly available as a benchmark for future work in this field.
READ FULL TEXT