Unified Frequency Domain Analysis of Lightfield Cameras

This paper presents a theory that encompasses both “plenoptic” (microlens based) and “heterodyning” (mask based) cameras in a single frequency-domain mathematical formalism. Light-field capture has traditionally been analyzed using spatio-angular representation, with the exception of the frequency-domain “heterodyning” work. In this paper we interpret “heterodyning” as a general theory of multiplexing the radiance in the frequency domain. Using this interpretation, we derive a mathematical theory of recovering the 4D spatial and angular information from the multiplexed 2D frequency representation. The resulting method is applicable to all lightfield cameras, lens-based and mask-based. The generality of our approach suggests new designs for lightfield cameras. We present one such novel lightfield camera, based on a mask outside a conventional camera. Experimental results are presented for all cameras described.