Efficient patch-based approach for compressive depth imaging

We present efficient camera hardware and algorithms to capture images with extended depth of field. The camera moves its focal plane via a liquid lens and modulates the scene at different focal planes by shifting a fixed binary mask, with synchronization achieved by using the same triangular wave to control the focal plane and the pizeoelectronic translator that shifts the mask. Efficient algorithms are developed to reconstruct the all-in-focus image and the depth map from a single coded exposure, and various sparsity priors are investigated to enhance the reconstruction, including group sparsity, tree structure, and dictionary learning. The algorithms naturally admit a parallel computational structure due to the independent patch-level operations. Experimental results on both simulation and real datasets demonstrate the efficacy of the new hardware and the inversion algorithms.