Depth measurement from integral images through viewpoint image extraction and a modified multibaseline disparity analysis algorithm

Integral imaging is a technique capable of displaying images with continuous parallax in full natural color. This paper presents a method of extracting depth map from integral images through viewpoint image extraction. The approach starts with the constructions of special viewpoint images from the integral image. Each viewpoint image contains a two-dimensional parallel recording of the three-dimensional scene. A new mathematical expression giving the relationship between object depth and the corresponding viewpoint image pair displacement is derived by geometrically analyzing the integral recording process. The depth can be calculated from the corresponding displacement between two viewpoint images. A modified multibaseline algorithm, where the baseline is defined as the sample distance between two viewpoint images, is further adopted to integrate the information from multiple extracted viewpoint images. The developed depth extraction method is validated and applied to both real photographic and computer generated unidirectional integral images. The depth measuring solution gives a precise description of the object thickness with an error of less than 0.3% from the photographic image in the example.