RESOLUTION ADJUSTMENT OF AN IMAGE THAT INCLUDES TEXT UNDERGOING AN OCR PROCESS

摘要

An optical character recognition process characterizes text lines in a textual image by their base-line, mean-line and x-height. The base-line for at least one text line in the image is determined by finding a parametric curve that maximizes a first fitness function that depends on the values of pixels through which the parametric curve passes and pixels below the parametric curve. The mean-line is determined by incrementally shifting the base-line upward by predetermined amounts (e.g., a single pixel) until a second fitness function for the shifted base-line is maximized. The second fitness function is essentially the inverse of the first fitness function. Specifically, the second fitness function increases with increasing lightless of pixels immediately above the shifted base-line while also increasing with decreasing lightness of pixels through which the shifted base-line passes.