Optimising point spread function of spatial filter

摘要

Design of an optical system (32) incorporating an optical spatial filter (36) uses a software model to optimise the point spread function of an image, by varying both (i) the distance between the image and spatial filter (36) and (ii) the bidirectional scattering transmission function of the spatial filter (36). The spatial filter (36) can be a holographic diffuser for abating colour moire interference arising from multi-layered LCD screens (33,34). The optimisation can take into account the contrast sensitivity function of the human visual system.