Depth-image-based rendering for 3DTV service over T-DMB

In this paper, we present a depth-image-based rendering (DIBR) technique for three-dimensional television (3DTV) service over terrestrial-digital multimedia broadcasting (T-DMB). 3DTV service over T-DMB is very attractive because the single user environment of T-DMB is suitable to glassless 3D viewing. However, the bit budget for the transmission of additional data in 3DTV service is very limited in T-DMB. DIBR can resolve this problem because the depth information as the additional data can be compressed effectively. However, DIBR has also some problems such as the backward compatibility with the conventional T-DMB, a large computational cost for rendering virtual images and generation of holes by disocclusion. To solve these problems, we first present the service architecture for DIBR-based 3DTV service over T-DMB, which can maintain the backward compatibility with the conventional T-DMB. Second, we propose a new depth preprocessing method based on adaptive smoothing. In the proposed depth preprocessing method, two adaptive smoothing filters of the discontinuity-preserving smoothing and the gradient direction-based smoothing are sequentially conducted. As a result, both the reduction of bitrates required for the depth transmission and the reduction of the holes can be achieved. Finally, we present look-up table (LUT)-based simultaneous method for generating an auto-stereoscopic image so that problems of the limited memory and the large computational cost can be resolved in T-DMB player. Various experiments show that the proposed DIBR technique can be efficiently employed for 3DTV service over T-DMB. (c) 2008 Elsevier B.V. All rights reserved.