EDGE DIRECTION DETECTION DEVICE, EDGE CORRECTION DEVICE, EDGE DIRECTION DETECTION METHOD AND EDGE CORRECTION METHOD

摘要

An edge direction detection device (1100) is provided with: a first filter unit (1110) that scans each target pixel included in an image, and for each of four directions placed at equal intervals, subjects the pixel values of multiple pixels positioned in the applicable direction, to a first filter process that extracts the value of a frequency component forming an outline in the image; and an edge direction evaluation unit (1120) that evaluates the direction of an edge, as being the direction perpendicular to the direction for which the value extracted by the first filter process was the maximum. For each of the four directions, the first filter unit (1110) applies the first filter process to the pixel value of each target pixel, and to the pixel value of each surrounding pixel on both sides of the target pixel in the applicable direction, separated by at least 2 pixels therefrom.