Patent ID: 8818099

Claim:
A method for processing a gray scale document image, the document image including text areas, the method comprising: (a) calculating phase congruency maps from the gray scale document image, including calculating a plurality of phase congruency maps at different orientations and calculating a combined phase congruency map by combining the plurality of phase congruency maps at different orientations; and (b) segmenting the gray scale document image into text areas and non-text areas using the phase congruency maps, comprising: (b1) performing a texture analysis using the phase congruency maps at different orientations and the combined phase congruency map; (b2) extracting edges from the combined phase congruency map to generate a binary edge map; (b3) extracting connected components from the binary edge map and generating a list of connected components; (b4) obtaining statistical characteristics of the connected components; and (b5) based on a result of the texture analysis of step (b1) and the statistical characteristics of the connected components obtained in step (b4), segmenting the gray scale document image into text areas which have higher probabilities of containing text and non-text areas which have lower probability of containing text.