METHOD AND CIRCUIT FOR EMPHASIZING CONTOUR

More natural contour emphasizing processing is performed by detecting the direction of a contour with respect to a point where horizontal and vertical contours cross and a diagonal contour point. The times of an objective pixel and all the pixels adjacent to the objective pixel in the horizontal, vertical, diagonal directions are made to agree with one another, contour emphasis values weighted with respect to the brightness of the pixel that has the largest difference in brightness among the pixels adjacent in the directions and the brightness of the objective pixel are calculated and added to the objective pixel. In order to solve the problem in a diagonal contour point, if two weighted continuous contour emphasis values have the same signs, the before and after contour emphasis values are adopted, and otherwise, diagonal optimization that the before and after contour emphasis values are made zero is performed and they are added to the objective pixel. Thus, more natural contour emphasis is performed.