Fig. 4

On the left, some example patches are shown. The patches are indexed by their top left corner. Usually the patches are fully overlapping, and a region of pixels around the perimeter of the image has fewer patches per pixel. The illustration on the leftshows how many times a pixel is contained in an 8×8 patch depending on the location in the image. An N _y ×N _x pixel image has (N _y −7)(N _x −7)≈N _y N _x fully overlapping patches. This method of sampling images is the key to many computer vision algorithms. The image of Park Avenue, in Arches National Park, was photographed by the U.S. National Park Service and is in the public domain