How can I frame the code for this condition

Suppose I have two monochromatic images one image is bigger one with let say size 256x120 and one small image with dimension 8x8. Now I want to design code to traverse Big_Picture and find all pixel locations in it where a ‘match’ with Small_Picture is found with condition as under: a) There are no less than 8x8pixel elements to compare (boundary case - eliminates any of last 7 row and column pixels from being a match location) b) Each pixel of Big_Picture is either less than or equal to corresponding Small_Picture pixel value c) There are at least 50% pixels that satisfy above criteria b

[Jan]

What have you tried so far and which problems have occurred?