EDGE DETECTION

摘要

An edge detection method and apparatus are disclosed. The method comprises the steps of preprocessing the digital image to reduce its resolution and smooth noise (100); calculating a pixel gradient value for each of a plurality of pixels of a digital image (110), the pixel gradient value representing the difference of a pixel value with respect to at least one neighbouting pixel; for each of a plurality of binarization threshold values, determining a corresponding edge map representing the location of pixel gradient values exceeding the binarization threshold value with respect to a side of the digital image (120); for each edge map, computing a measure of linearity; determining an optimal binarization threshold value based on the computed measures of linearity (130); and selecting the edge map corresponding to the optimal binarization threshold value (140).