A parallel algorithm, operating on a pyramid computer, that performs template matching on a binary-value image is presented. Both the image and the template are represented by their quadtrees.

For an N × N image with an M × M template on a ( log N + 1 )-level pyramid computer, the time complexity of the algorithm is bounded above by &agr; log N + &bgr; M², where &agr; and &bgr; are constants. This complexity is the same, except for the value of the constants, as that of an alternate algorithm that is cited.