A method of mapping a first array to a second array is useful where (1) each of the arrays has pixels in sequential columns and rows and the first array has sequential integers identifying each row of pixels, (2) sequential integers identify each column of pixels, and a numerical value is associated with each pixel, (3) the first and second arrays have (or can be made to have) a one to one pairing between columns of the first and second arrays, and (4) groups of four unique pixels in the same column of the first array are paired one to one with a pixel in the paired column of the second array. The method includes the steps of, for each column in the first array, selecting the values associated with the pixels in four sequential odd numbered rows to form an odd group of four unique pixels, combining the values associated with the pixels in the first three odd numbered rows of the odd group to form an odd combined value, and mapping the odd combined value to the pixel in the column and row of the second array with which the odd group is paired, and thereafter selecting the values associated with the pixels in four even numbered rows to form an even group of four unique pixels, combining the values associated with pixels in the last three rows of the even group to form an even combined value, and mapping the even combined value to the pixel in column and row of the second array with which the even group is paired.