Edge direction determination device, edge direction determination method and the edge direction determination program

摘要

PROBLEM TO BE SOLVED: To provide an edge direction determination device which can determine an edge direction of an image with high accuracy even when the image has much noise.SOLUTION: An edge direction determination device 1 includes: block extracting means 21 for extracting a block including a plurality of pixels centering on an attention pixel; area setting means 22 for setting a criterion area constituted by a plurality of pixels centering on the attention pixel in the block extracted by the block extracting part, and setting a plurality of reference areas of the same shape as the criterion area at a position, which is mutually displaced from the criterion area, with respect to each of a plurality of directions starting from the attention pixel serving as an original point; representative value calculating means 23 for calculating, as to the plurality of directions, for each of the directions, a representative value indicative of a similarity of pixel values between the reference area which belongs to the direction and the criterion area; and edge direction determination means 24 for obtaining a direction exhibiting a highest similarity between the criterion area and the reference area using representative values of the respective plurality of directions so as to determine the direction exhibiting the highest similarity as an edge direction in the attention pixel.