| 发明名称 | Data generation method and data generation apparatus | ||
| 摘要 | Conventional calibration patches are designed such that gradation values of the patches are determined, based on the overall length of a trajectory of a monochrome ink color in an L*a*b* space, so that distances between patches become uniform, and therefore provide low interpolation accuracy in a region where measurement values change non-linearly in accordance with the change in gradation.;According to the present invention, gradation values of patches to be used for color calibration are determined so that the patches are closely arranged in a region where measurement values change non-linearly in accordance with the change in gradation. Thus, interpolation accuracy can be improved in a region where measurement values change non-linearly. | ||
| 申请公布号 | US8792134(B2) | 申请公布日期 | 2014.07.29 |
| 申请号 | US201213725639 | 申请日期 | 2012.12.21 |
| 申请人 | Canon Kabushiki Kaisha | 发明人 | Omagari Yuki;Uratani Mitsuru;Ishida Yuki;Hiyama Yutaka;Obayashi Masaaki |
| 分类号 | G06K15/00;H04N1/46;G03F3/08;H04N1/60;G06K9/00 | 主分类号 | G06K15/00 |
| 代理机构 | Canon USA Inc IP Division | 代理人 | Canon USA Inc IP Division |
| 主权项 | 1. A data generation method for generating patch recording data used to record correction patches corresponding to M (where M is a natural number) gradation values to be used for color calibration, the data generation method comprising: a recording step of recording N patches corresponding to densities of N (where N is a natural number and M<N) gradations; a first calculating step of calculating a correction coefficient for each of L (where L is a natural number and 3≦L≦N) gradation values selected from among the N gradations, by using an absolute value of a difference vector between a unit vector of a first vector and a unit vector of a second vector for three consecutive gradations having, in sequence, a first gradation, a second gradation, and a third gradation among the L gradation values, the unit vector of the first vector and the unit vector of the second vector being calculated based on the first vector and the second vector, the first vector representing a difference between a measurement value of the second gradation and a measurement value of the first gradation by using a plurality of parameters, the second vector representing a difference between a measurement value of the third gradation and the measurement value of the second gradation by using the plurality of parameters; a second calculating step of calculating a correction coefficient for correcting a measurement value, for each of N measurement values on the basis of the L correction coefficients calculated in the first calculating step; a generating step of correcting a color difference of measurement value between gradations of the N gradations by using the N correction coefficients calculated in the second calculating step, and generating N correction values corresponding to the N gradations; and a determining step of determining the M gradation values as gradation values for the correction patches from among the N gradations on the basis of the N correction values. | ||
| 地址 | Tokyo JP | ||