Patent ID: 8374892

Claim:
A method of retrieving a tumor contour implemented in an image processing system that includes a memory storing a grayscale image, a display screen, an input device and a processor performing method steps, comprising: receiving an input tumor contour of the grayscale image; defining a tumor contour annular region and a plurality of reference segments of the grayscale image, wherein the input tumor contour is in the tumor contour annular region, and each of the plurality of reference segments is across the tumor contour annular region and includes a plurality of measured points; retrieving a tumor contour suggestion point on each of the plurality of reference segments; and linking all the tumor contour suggestion points on all of the reference segments, for forming the tumor contour, wherein each of the plurality of reference segments includes a plurality of local segments and each of the plurality of local segments includes a plurality of moving horizons; wherein each of the plurality of local segments consists of one of the plurality of measured points, at least one measured point before and at least one measured point after the one of the plurality of measured points, and each of the plurality of moving horizons consists of one of the plurality of measured points in the corresponding local segment and at least one measured point after the one of the plurality of measured points; and wherein the tumor contour suggestion point is retrieved by a moving variance retrieving method comprising the steps of: calculating a gradient variance of the grayscale image in the plurality of local segments and an average gradient variance of the grayscale image in the plurality of moving horizons; calculating the ratio of the gradient variance of the grayscale image in the plurality of local segments to the average gradient variance of the grayscale image in the plurality of moving horizons; and retrieving the measured point corresponding to the maximum ratio as the tumor contour suggestion point.