Patent Document ID: 20110026813
Application ID: 12439694
Patent Status: 0

Claim One:
1. A method for converting an image of text comprising background and foreground graphical representations of elements to a binary image representation of the image in a computer system, by using a threshold technique, the method comprises the steps of: a) providing an analysis of the background by identifying whitest pixel levels in the image, section by section, and record the positions of the whitest pixels as a whitest pixel path, b) using the recorded whitest pixel path to estimate the local background level of the image, is c) selecting a sub-image part of the image and investigate if there are text elements in the sub-image part, d) if no text element is identified in c), select another next sub-image part and investigate if there is a text element in this next sub-image part, e) repeat step c) and d) until a text element is identified, f) use an edge detector on the sub-image comprising the identified text element, g) use the identified pixel positions of the edges to generate a histogram of grey levels of the edges, h) use the histogram of the grey levels of the edges to derive a local threshold level, and use the estimated local background level of the image to provide the relative threshold level of the image as being proportional to the difference between the local threshold and the estimated background, i) use the relative threshold value to convert the image to a binary image representation of the image.