高准确度光学系统中材料非均匀性对成像质量的影响

利用Zernike多项式对用Zygo干涉仪测得的离散材料折射率数据进行了拟合,再使用光线光学的方法评价了系统的成像质量. 由于材料折射率分布的无规则性,在对包含非均匀介质的实际光学系统的模拟仿真和优化时,需要考虑选取材料不同部位加工成的透镜会对系统成像质量有不同的影响,而且加工好的透镜在装配过程中,绕着光轴旋转不同的角度同样会影响成像质量. 通过计算机模拟的方法预先选取材料的最佳部位以及找到最好的装配位置,从而提高了光学系统的性能.

A Novel Quality Evaluation Method for False Color Fused Image Based on Human Visual System

With the development of image fusion technology, various fusion methods are proposed. However, in many cases, the final fused image is observed by human eyes. As a result, fused image quality assessment based on human visual system is particularly important. In order to obtain the objective quality evaluation by simulating human eye perception, a novel method is proposed. First, the source images and the fused image are transformed into CIE L^*a^*b^* color space respectively. Then in the frequency domain these images are filtered by the contrast sensitivity function. The richness of details of the fused image can be predicted by calculating the chromatism of it. With the increasement of the chromatism value, the information details also increase. While the correlation coefficient is evaluated at the same time by calculating the chromatism among the source images and the fused image. The higher the correlation coefficient, the better the fusion algorithm. With these two constrained parameters, a judgement can be given to different evaluation algorithms. Experiments show that the results of the proposed method are consistent with the human eye observation.