| 摘要 |
PROBLEM TO BE SOLVED: To provide an image processor having a shading correction circuit capable of realizing the reduction of a memory capacity, the reduction of a circuit scale, and the improvement of a calculation speed. SOLUTION: The image processor has a shading correction coefficient storage 104 which stores a plurality of shading correction coefficients corresponding to the distance from the center of the optical axis to a plurality of reference points, an approximate coefficient calculator 203 which calculates an approximate coefficient from horizontal and vertical components of the distance from the center of the optical axis to a target pixel, an adder 204 for adding the horizontal and vertical components, and a multiplier 205 for multiplying the approximate coefficient by at least either of the horizontal component and the vertical component. The shading correction circuit is composed of a distance approximate value calculation circuit 101 for calculating an approximate value of the distance from the center of the optical axis to the target pixel, a target pixel/reference point positional relation calculation circuit 103 for calculating the positional relation between the target pixel and the reference point, and an interpolation calculator 105 for executing interpolation calculation of a shading correction coefficient of the target pixel from the obtained positional relation and the shading correction coefficient. COPYRIGHT: (C)2005,JPO&NCIPI
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