A fast algorithm for computing histograms on a reconfigurable mesh

The authors present fast parallel algorithms for computing the histogram on PARBUS and RMESH models. Compared with the approach of J. Jeng and S. Sahni (1992), the proposed algorithm improves the time complexity by using a constant amount of memory in each processing element. In the histogram modification algorithm, the entire range of h is considered. The connections used by the proposed algorithm on the PARBUS model are same as those allowed in the MRN model. Thus, this algorithm runs on this model as well. The results obtained imply that the number of 1´s in a N×N 0/1 table can be counted in O(log* N) time on an N×N reconfigurable mesh and in O(log log N) time on an N×N RMESH