ADAPTIVE DOCUMENT BINARIZATION - A Human Vision Approach
Vassilios Vonikakis, Ioannis Th. Andreadis, N. Papamarkos, Antonios C. Gasteratos · 2007
Abstract: This paper presents a new approach to adaptive document binarization, inspired by the attributes of the Human Visual System (HVS). The proposed algorithm combines the characteristics of the OFF ganglion cells of the HVS with the classic Otsu binarization technique. Ganglion cells with four receptive field sizes tuned to different spatial frequencies are employed, which, adopting a new activation function, are independent of gradual illumination changes, such as shadows. The Otsu technique is then used for thresholding the outputs of the ganglion cells, resulting to the final segmentation of the characters from the background. The proposed method was quantitatively and qualitatively tested against other contemporary adaptive binarization techniques in various shadow levels and noise densities, and it was found to outperform them. 1