Patent ID: 8787653

Claim:
A circuit for determining an orientation direction of a color edge at a pixel location in a color image, said system comprising: a first tier of circuitry receiving, as input, eight pixel counts each comprising a total number of pixels of a color in a region of a window centered on a selected pixel in a bitmap of a halftoned color image, said first tier circuit generating, as output, four largest pixel counts of said eight input pixel counts and four 1 st tier control bits used to select said four largest pixel counts; a second tier of circuitry receiving, as input, said four 1 st tier control bits and said four largest pixel counts, said second tier circuit generating, as output, two 2 nd tier control bits used to select two of the highest pixel counts of said four largest pixel counts, and to select two of said four 1 st tier control bits; and a third tier of circuitry receiving, as input, said two selected highest pixel counts, two of said selected 1 st tier control bits, and two of said selected 2 nd tier control bits, said third tier of circuitry generating, as output, a 3 rd tier control bit used to select one of said two selected 1 st tier control bits, one of said two 2 nd tier control bits, and a maximum pixel count of said two highest pixel counts, said selected 1 st , 2 nd and 3 rd tier control bits comprising a 3-bit word which defines an orientation direction of said color edge.