Depth Reconstruction Filter and Down/Up Sampling for Depth Coding in 3-D Video

A depth image represents three-dimensional (3-D) scene information and is commonly used for depth image-based rendering (DIBR) to support 3-D video and free-viewpoint video applications. The virtual view is generally rendered by the DIBR technique and its quality depends highly on the quality of depth image. Thus, efficient depth coding is crucial to realize the 3-D video system. In this letter, we propose a depth reconstruction filter and depth down/up sampling techniques to improve depth coding performance. Experimental results demonstrate that the proposed methods reduce the bit-rate for depth coding and achieve better rendering quality.

I. Introduction

A depth image represents a relative distance from a camera to an object in the three-dimensional (3-D) space, and is widely used in computer vision and computer graphics fields to represent 3-D scene information. Most image-based rendering (IBR) methods [1] utilize the depth image in conjunction with stereo or multiview video to realize 3-D and free-viewpoint video applications [2]–[7]. Efficient coding of both the depth image and the multiview video and rendering techniques are key issues for such applications.