| 摘要 |
PROBLEM TO BE SOLVED: To specify each region of repetitive patterns reliably, using only a pattern irradiation method. SOLUTION: Three sheets of sinusoidal patterns whose phases are shifted from each other byπ/4 individually are projected from a projector 1, and a relative phaseψr is found for each pixel from each reflected image by the principle of a phase shift method. An absolute phaseψa which is obtained by excluding unsteadiness of a period of 2πfrom the relative phaseψr corresponds to an irradiation angle, and a distance can be computed for each pixel from the principle of triangulation. Next, the projector 1 projects three kinds of patterns in the shape of steps and a white flat pattern. These patterns in the shape of steps are different in distribution of the three colors of red, green, and blue (R, G, B) individually. Since an intensity ratio of the three colors is different in each subpattern, a subpattern number of the repetitive patterns can be specified, and an absolute phase can be found from a relative phaseψ, by finding an intensity ratio of the three colors with respect to the flat pattern from reflected images of these four-in-total patterns. COPYRIGHT: (C)2004,JPO
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