Compression comparisons for multiview stereo

Abstract

Summary form only given. Multiview stereo imaging uses arrays of cameras to capture scenes from multiple perspectives. This form of imagery is used in systems that allow the user to survey the scene, for example by head motion. Very little work has been reported on compression schemes for multiview images. Multiview image sets tend to be very large because they may contain several hundred views, but there is considerable redundancy among the views which makes them highly compressible. This paper compares methods for compressing large multiview stereo image sets. There is an obvious similarity between multiview image sets and video sequences. As a baseline we compressed a set of multiview stereo images with JPEG on each image individually and MPEG-1 applied to the whole set. The average bits per pixel were reduced by roughly a factor of two over individual frame compression, at constant mean square error (MSE). Stereo specific perceptual distortions can be viewed in anaglyph representations of the data set. Another method, unique to this data type, is based on residual coding with respect to a synthetic "panoramic still" containing information from all of the images in the set. In this method we synthesize a single panoramic image from all of the members of a registered set, code the panoramic image, and then code the residual images formed by subtracting the individual images from the corresponding position on the panorama. Initial results with this method appear to give a similar MSE rate distortion curve as the MPEG based techniques. However, the panoramic still method is inherently random access.