| 摘要 |
The method is for automatic astigmatism correction of a lens system. A first image is provided that is not in focus at a first stigmator setting of a set of lenses. A calculating device calculates a corresponding first Fourier spectrum image. A distribution and direction of pixels of the Fourier spectrum image are determined by calculating a first vector and a second vector. The first vector is compared with the second vector. The lens system is changed from a first stigmator setting to a second stigmator setting to provide a second image. A corresponding Fourier spectrum image is calculated. The distribution and direction of pixels of the second Fourier spectrum image is determined by calculating a third vector and a fourth vector. The third vector is compared to the fourth vector. The image that has the lowest vector ratio is selected. |
