Patent Document ID: 5428377
Application ID: 07927983
Patent Status: 1

Claim One:
1. A color spatial filtering apparatus for improving black quality and reducing intercolor bleeding in a color ink jet printer, comprising: input signal receiving means for receiving input data signals representing a color image in a predetermined color space in color pixel planes, one color pixel plane representing each color of the color space; a buffer for storing said data signals; summing means for summing said color pixel planes into a composite pixel plane; examining means for incrementally examining each pixel and a surrounding matrix of pixels around each said pixel in the composite pixel plane, said examining means determining for each pixel whether said pixel is black and, if so, further determining whether said surrounding matrix of pixels contains (a) adjacent blank areas, (b) adjacent non-black color areas, or (c) adjacent black areas; logic means for determining a preferred representation of each pixel, based on a predetermined set of rules for increasing black picture quality and minimizing intercolor bleed, said rules including (a) representation of black pixels for subsequent printing by a first ink having a predetermined bleed characteristic when said surrounding matrix of pixels is determined to contain one of the group of adjacent black areas and adjacent blank areas and (b) representation of black pixels for subsequent printing by a second ink having a lesser bleed characteristic when said surrounding matrix of pixels is determined to contain adjacent color areas; and update means for updating said color pixel planes with an updated representation of each said pixel in the buffer as determined by said logic means.