Quadtree Algorithms for Template Matching on Mesh Connected Computer

We present four algorithms to perform template matching of an N×N image with an M×M template. The first algorithm is sequential, and the others are based on a SIMD mesh connected computer with N×N processors. In the first three algorithms, both the image and the template are represented by quadtrees, whereas in the last one, the template is represented by a quadtree, and the image is represented by a matrix. The time complexities of the four algorithms are respectively upper-bounded by α1N2M2, α2N+β2M2, α3N+β3M2, and β4M2, where α1, α2, β2, α3, β3, and β4 are constants.