An improved RL-IBD restoration algorithm for wavefront coded imaging system

A spherical coded imaging system combined with a controlled spherical aberration lens system and a digital sharpening filter can realize a fast and low-cost extended depth of field (EDoF) imaging system. At the same time, the wavefront coding technology is introduced, which can not only extend the depth of focus of the system, but also suppress the aberration including spherical aberration in the system design. However, for the wavefront coding system, due to the modulation of the incident light wave, the light distribution is more diffuse, so the blurred image generated by the wavefront coding system is a blurred image. It is necessary to decode and restore the intermediate blurred image to obtain a clear target image. In view of the lack of convergence and reliability of IBD algorithm, the Richardson-Lucy(RL) algorithm is introduced into RL-IBD algorithm, which can effectively reduce the sensitivity of the algorithm to noise. On the basis of vector extrapolation and exponential correction, this paper proposes improvements to the RL-IBD algorithm, which enhances the stability of the algorithm, and improves the convergence speed, noise suppression ability and adaptability of the algorithm.