| 摘要 |
PROBLEM TO BE SOLVED: To extract a halftone dot region even if a halftone dot process condition including the number of screen lines, screen angle of binary image information subjected to a halftone dot process is not clear.SOLUTION: An original image is decomposed into strips (square range), and a halftone dot region is extracted in an entire square range. The extraction of the halftone dot region is executed by a plurality of number of times with a strip width (Y-direction pixel number) varied, and the halftone dot region is specified by a logical sum of them. Then, the original image is rotated by 90°. Binary image data having been rotated by 90° is decomposed in strips (square range), and a halftone dot region is extracted in an entire square range. The extraction of the halftone dot region is executed by a plurality of times with the strip width (Y-direction pixel number) varied, and the halftone dot region is specified by the logical sum of them. Lastly, the obtained halftone dot regions are synthesized, and further, the logical sum process is executed to finally specify a halftone dot region.SELECTED DRAWING: Figure 9 |
