Color Demosaicing in Plenoptic Cameras

A plenoptic camera captures the 4D radiance about a scene. Recent practical solutions mount a microlens array on top of a commodity SLR to directly acquire these rays. However, they suffer from low resolution as hundreds of thousands of views need to be captured in a single shot. In this paper, we develop a simple but effective technique for improving the image resolution of the plenoptic camera by maneuvering the demosaicing process. We first show that the traditional solution by demosaicing each individual microlens image and then blending them for view synthesis is suboptimal. In particular, this demosaicing process often suffers from aliasing artifacts, and it damages high frequency information recorded by each microlens image hence degrades the image quality. We instead propose to demosaic the synthesized view at the rendering stage. Specifically, we first transform the radiance to the desired focal plane and then apply frequency domain plenoptic resampling. A full resolution color filtered image is then created by performing a 2D integral projection from the reparameterized radiance. Finally, we conduct demosacing to obtain the color result. We show that our solution can achieve visible resolution enhancement on dynamic refocusing and depth-assisted deep focus rendering.