A 4-D dual-fan filter bank for depth filtering in light fields

Abstract—A light field is a four-dimensional (4-D) representa-tion of the light permeating a scene—it parameterizes light rays as a function of position and direction. Such a structure can be mea-sured using a specialized camera and can be used to render novel views of the scene it represents. It has previously been shown that the light field model of a scene may be filtered for a single depth by employing frequency-planar filters. Here, we show how a light field may be selectively filtered for a range of depths by forming a 4-D frequency passband that surrounds the intersection of two 4-D fans. A newly proposed cascaded filter bank is shown to ap-proximate this passband, and its effectiveness is demonstrated on two scenes, both of which contain occlusions. Results are compared with those previously obtained using 4-D frequency-planar filters. Index Terms—Filter banks, four-dimensional fan filters, four-dimensional signal processing, image analysis, light fields. I