Direct search coding algorithm with reduction in computing time by simultaneous selection rule

An optimized encoding algorithm is required to produce high-quality computer-generated holograms (CGHs). For such a purpose, I have proposed that the use of the direct search algorithm (DSA) is effective for encoding the amplitude and phase in the Lohmann-type CGH. However, it takes much computation time to obtain an optimum solution by the DSA. To solve this problem, I have newly found that the simultaneous direct search algorithm (SDSA) is greatly effective for shortening the computation time for encoding the Lohmann-type CGH. As a result, the evaluation value of the reconstructed image for the SDSA is the same as that of 0.992 for the DSA. The computation time for the SDSA is drastically shortened from 3575 to 55 s for the DSA.