Patent ID: 6778700
Filing Date: 2004-08-17
Classification: G06K

Abstract:
A method having scanned intensity information as input for detecting text in a scanned page by observing a very strong contrast in a localized region that comprises a substantially sharp edge between a dark side and a light side, the method comprising:pre-processing by detecting a local ramp, identifying an intensity trough, and determining a stroke width, wherein local ramp detection comprises using a threshold value and nine 3Ã—3 high-pass filters to obtain nine filtered values per pixel, and determining therefrom any of a vertical ramp detection value, a horizontal ramp detection value, a diagonal ramp in vertical direction detection value, and a diagonal ramp in horizontal direction detection value; and contrast-based text detection processing, whereby any of black text on white background, black text on color background, and white or light text on a dark background are detected.