1. A method of calculating an output pixel by characterizing structures in a plurality of pixels; the method comprising: generating a smoothed pixel using a current pixel and the plurality of pixels; generating a plurality of structure checksum bit groups by comparing a pixel value of each pixel in the plurality of pixels with the smoothed pixel; combining the structure checksum bit groups to form the structure checksum; indexing a table of structure characteristics with the structure checksum to select a structure characteristic corresponding to the structure checksum; and setting the output pixel equal to the current pixel when the structure characteristic is a first value; and setting the output pixel equal to the smoothed pixel when the structure characteristic is a second value, wherein the second value is different from the first value.