Investigation of extended depth-of-field f/8 camera with optimized cubic phase mask and digital restoration

Abstract

An investigation of extended depth-of-field camera with optimized phase mask and digital restoration is presented. The goal of this paper is to implement the wavefront coding technique without affecting much of the original design, and the design has taken the complexity of imaging system into consideration. The optimized strength of cubic phase mask (CPM) is based on the analytical optimal solution for the task-based imaging system [J. Opt. Soc. Am. A 25, 1064 (2008)]. The noisy intermediate images of CPM system with highest spatial frequency of interest can be effectively restored by vector-based Richardson-Lucy algorithm. Restoration from the system with generalized CPM produces precise image position than the system with CPM does. In general, the CPM system procures modulation transfer function higher than 0.195 in the whole depth-of-field, and the mean squared error of the restored images are less than 5 %.

End-to-end optimization of optical systems with extended depth of field under wide spectrum illumination

“…Then, Stork and Robinson [25] introduced joint optimization of optical systems and digital restoration algorithms, and this combined approach was applied to the optimization of DOF extending masks by Diaz et al [3,4]. This kind of approach is now extended to many forms of phase masks [15,22,14,20,1,30], and to the use of neural networks [24,7,13,16,26,27].…”