An Optimization Algorithm for Polarizer-Free Imaging of Liquid Crystal Lens

Owing to its ability of focus change not relying on any mechanical movements, liquid crystal lens is expected to be used in many fields such as robot vision, automatic pilot, and depth measurement. In the liquid crystal lens vision imaging system, in order to obtain high-contrast images without a polarizer, an optimization algorithm for polarizer-free imaging of liquid crystal lens is proposed. Image edge reflects the main contour information, and it decides the contrast of the image, so in the algorithm image edge is extracted first, then image processing is carried out with out-of-focus image and in-focus image in the edge parts, but not in the smooth area. Low frequency components caused by non-modulated ordinary wave are removed to improve image edge contrast and suppress noise in the smooth area. Experiments show that the optimized algorithm enhances the contrast of image edges, and the image noise is reduced by 50% compared with the algorithm before optimization.