Cells detecting the boundary of a surface are subject to less lateral inhibition than cells detecting the center of the same surface. This leads to an effect called

edge enhancement

Explanation:

Edge Improvement is an image processing filter that enhances the edge contrast of an image or video in an effort to improve its sharpness. Edge enhancement does not enhance subtle details found in more uniform areas of the image, such as texture or grain appearing in flat or smooth areas of the image. The filter works by marking the sharp edge boundaries of the image, the edge between a subject and the contrasting color background, and increasing the image contrast in the area around the edge.