Computer-readable storage medium, image processing apparatus, and method for image processing

An image processing apparatus, comprising:

• a memory configured to store data, and
• a controller configured to:
• obtain subject image data composing a subject image;
• set a plurality of larger regions and a plurality of smaller regions in each of the plurality of larger regions in the subject image with use of the subject image data, each of the plurality of smaller regions being smaller than the larger region in which the plurality of smaller regions are set, each of the plurality of larger regions including a plurality of pixels, each of the plurality of smaller regions including a plurality of pixels;
• calculate a first feature amount of each of the plurality of smaller regions and a second feature amount of each of the plurality of larger regions, the first feature amount being calculated with use of values of the plurality of pixels in each of the plurality of the smaller regions, the second feature amount being calculated with use of values of the plurality of pixels in each of the plurality of the larger regions;
• determine whether each of the plurality of smaller regions is an edge region including an edge based on a comparison between the first feature amount of the smaller region and the second feature amount of the larger region in which the smaller region is set;
• and
• generate edge image data indicating edges in the subject image with use of results of the determination whether each of the plurality of smaller regions is an edge region.

A method to process images, comprising:

• obtaining subject image data composing a subject image;
• setting a plurality of larger regions and a plurality of smaller regions in each of the plurality of larger regions in the subject image with use of the subject image data, each of the plurality of smaller regions being smaller than the larger region in which the plurality of smaller regions are set, each of the plurality of larger regions including a plurality of pixels, each of the plurality of smaller regions including a plurality of pixels;
• calculating a first feature amount of each of the plurality of smaller regions and a second feature amount of each of the plurality of larger regions, the first feature amount being calculated with use of values of the plurality of pixels in each of the plurality of the smaller regions, the second feature amount being calculated with use of values of the plurality of pixels in each of the plurality of the larger regions;
• determining whether each of the plurality of smaller regions is an edge region including an edge based on a comparison between the first feature amount of the smaller region and the second feature amount of the larger region in which the smaller region is set;
• and
• generating edge image data indicating edges in the subject image with use of results of the determination whether each of the plurality of smaller regions is an edge region.