| 摘要 |
PROBLEM TO BE SOLVED: To provide a dot pattern forming apparatus and a set of threshold matrices which are capable of reducing the graininess in a color image formed by overlaying (superimposing) FM screen dot patterns for color separations. SOLUTION: A continuous-tone image of uniform density and the thresholds in the FM screen threshold matrices are compared to form dot patterns for CKM-separations by the dot pattern forming apparatus. When the dot patterns are transformed by FFT, frequency-domain data are obtained. The obtained frequency-domain data äAFFT2(2, 15(degrees):C), AFFT2(2, 75(degrees):K), and AFFT2(2, 45(degrees):M)} are substantially elliptical figures, and the directions of the major axes of the substantially elliptical figures differ from each other, then the graininess in the CMK-separation image formed by overlaying (superimposing) FM screen dot patterns for color separations. COPYRIGHT: (C)2007,JPO&INPIT
|
