| CPC G06T 7/001 (2013.01) [G06T 3/147 (2024.01); G06T 2207/30144 (2013.01)] | 7 Claims |
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1. A verification apparatus operable to (a) read a printed sheet to obtain a scanned image, and (b) perform verification processing for verifying whether there is an image defect in the printed sheet by comparing the scanned image and a correct image, the apparatus comprising:
a first reader that reads the printed sheet to generate image data;
a second reader that reads the printed sheet to generate image data, wherein respective items of the image data generated by the first reader and the image data generated by the second reader have an overlapping region in which they overlap; and
one or more controllers including at least one processor and at least one memory, wherein the one or more controllers are configured to:
(A) in generation of image data,
(1) extract feature points of respective items of image data generated by reading the printed sheet with the first reader and image data generated by reading the printed sheet with the second reader;
(2) determine whether any one of feature points of first image data generated by reading the printed sheet with the first reader corresponds to any one of feature points of second image data that should be generated by reading the printed sheet with the second reader;
(3) in a case where it is determined in the determining that a first feature point of the feature points of the second image data corresponds to any one of the feature points of the first image data, convert coordinates of the first feature point from a coordinate system of the second reader to a coordinate system of the first reader;
(4) in a case where it is determined in the determining that a second feature point of the feature points of the second image data does not correspond to any one of the feature points of the first image data, map coordinates of the second feature point on the coordinate system of the first reader; and
(5) store coordinates of feature points of the second image data in the coordinate system of the first reader, and store the first image data and the second image data as the scanned image or the correct image; and
(B) in the verification processing,
(1) calculate a geometrical conversion parameter from (a) the correct image generated in the generation of image data and (b) coordinates of the feature points of the correct image and (c) the coordinates of feature points of the scanned image generated in the generation of image data; and
(2) align the scanned image and the correct image based on the geometrical conversion parameter, and verify whether there is an image defect in the printed sheet.
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