| Summary: | 碩士 === 國立臺北科技大學 === 光電工程系 === 107 === As nanotechnology advances recently, submicron pixel of diffractive optical elements (DOEs) can be accurately manufactured and hence the number of pixels dramatically increased. The image quality of DOEs with a large amount of pixels is in general low using current optimization algorithms. We have studied the iterative Fourier transform algorithm (IFTA), the simulated annealing (SA) algorithm, and the pixelwise hybrid input-output (PHIO) algorithm, while none of them could result into high image quality of DOEs with millions of pixels. In the thesis, we present an algorithm and show its capability to yield DOEs achieving the high quality of image.
The proposed algorithm is composed of a modified IFTA and a modified PHIO, which is called the variable image error reduction algorithm (VIERA). VIERA was equipped with a dynamic range of image errors and a decreasing number of image pixels which were able to improve the image quality of DOEs in less computation time. In this study, the number of DOEs was 1920×1080 and the largest PSNR was 39, compared with the PSNR of 8 obtained using other algorithms.
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