Research on a novel image restoration algorithm for the wave-front coding system

In the optical imaging system, deep depth of focus brings larger imaging space, thereby obtaining more information from object space, but also correcting defocus error caused by variety reasons. Thus deep depth of focus has profound significance in the practical application. The information optical imaging system based on the wave-front coding is a general interest among the current research of focal depth extension area. A special designed phase mask been added in the optical system, which could encode object information obtained from the designed focal depth range. By this mean, the OTF and MTF become insensitive to defocussing. Thus equal blurred middle images could be obtained, being processed by phase mask decided by the optical system which was known both by designing and testing and digital image process technology, the final clear image with extended depth of focus could be acquired. In this paper, the detail of a novel image restoration algorithm for the wave-front coding system was discussed. We aim at a specific designed wave-front coding imaging lens, using the edge condition and wavelet transform for an improved Wiener filtering processing. The result of simulation and experimental shown this algorithm could quickly decode the obtained blurred middle image. In the premise of retain more details, this method could product a good image restoration within with whole range of the designed depth of focus. The peak of signal-to-noise (SNR) ratio and the information entropy have been promoted. So does the control of the blurred edge and the ringing effect.