Fast full search block matching using subblocks and successive approximation of the error measure

A fast full search block matching algorithm is developed. The matching criterion is the sum of absolute differences or the mean square error. The algorithm evaluates lower bounds for the matching criteria for subdivided blocks in order to reduce the number of search positions. It also uses the lower bounds for a fast calculation of the matching criterion for the remaining search positions. The computational complexity of the algorithm is evaluated and compared to the three-step search strategy. The search result of the algorithm is identical to the search result of the exhaustive search