Patent ID: 7324701

Claim:
A method for executing a noise reduction process to images composed of a plurality of pixels, the method comprising: calculating an edge level in target pixels that are an object of a smoothing process; determining an edge angle that is an angle of an array of edge-forming pixels including the target pixels based on the calculated edge level; obtaining a filter that has orientation properties extracting pixels in a given direction as reference pixels and matching the determined edge angle, wherein the filter is a median filter and the filter has an extraction area which is wider in a direction parallel to than in a direction perpendicular to the given direction; executing a first smoothing process on the target pixels using the filter that has been obtained; when the calculated edge level is lower than a prescribed edge level, calculating a size of an edge component of the target pixels; and executing a second smoothing process on the target pixels using a moving average filter having extraction areas that are smaller as the calculated size of the edge component increases.