Character recognition in degraded document images using morphological and phase-only filtering

Nowadays, new optical character recognition (OCR) algorithms for mobile devices are actively developed. Most of these algorithms work well with documents digitized under perfect conditions. When using mobile devices, document images are subject to various distortions, such as nonuniform and poor illumination, geometric distortions, low resolution, and sensor noise. In this paper, we propose a reliable method for recognition of contextually unrelated characters in degraded document images with the use of a bank of adaptive morphological and phase-only filters. With the help of computer simulation, the results of operation of traditional and proposed approaches to detection and classification of characters of the Latin alphabet in distorted document images are compared.