1. A computer implemented method, comprising: generating, for an array of values, a row array for each row in the array and a column array for each column in the array, wherein values in a given generated row array are indicative of local maxima of values in the corresponding row, wherein values in a given generated column array are indicative of local maxima of values in the corresponding column, and wherein the generating is performed by a computer; multiplying values in the generated row and column arrays to determine local maxima of the array, and wherein the multiplying is performed by the computer.