Edge Thinning Based on Sobel Operator
用Sobel算子细化边缘

A new edge thinning method based on Sobel operator is proposed in this paper. A gray edge image (P1) is obtained by introduces a attenuation factor,the gray edge image can also be processed using Sobel operator,then another gray edge image (P2) is get from the previous gray edge image. Another gray edge image(P3) is obtained by subtracting P2 from P1 and the pixels of negative value in P3 are set to zero to eliminate the extra points on both side of the detected edges therefor a image with thinner edge can be obtained. And this procedure can repeat several times to obtain thinner edges(but not necessarily continuous). This method also has effect on the edges that detected by other edge detection methods. Edge thinning can be used to get the exact position of object's edge. This method can not only get fairly thin edge but can also reserve the edges of low step change and this advantage can overcome the segmentation error that due to improperly selected threshold.