High-Bit-Depth Geometry Representation and Compression in MPEG Immersive Video System

Abstract

Immersive video has been rapidly evolving as a new form of media for virtual reality (VR) applications, increasing demand for efficient compression and transmission techniques. As immersive videos comprise multiple two-dimensional videos, compressing these videos individually incurs a high computational cost. MPEG has been standardizing immersive video coding, referred to as MPEG Immersive Video (MIV), wherein the redundant parts of immersive videos between views are pruned and combined into atlas videos, which are then coded using a conventional video codec. However, the original high-bit-depth geometry information is quantized to fit the conventional video codec during this process, leading to the loss of detailed sub-bit information. This paper presents a novel high-bit-depth geometry representation method, wherein the remaining bits after quantization are assigned to the chrominance channel to improve the performance of rendering the videos. Additionally, adequate preprocessing is proposed for bit assignment in the YUV 4:2:0 format. The performed experiments indicate that the proposed method reduces the BD-rate by approximately 7% on average by improving the rendering performance without modifying the existing MIV system.

Keywords

• High-bit-depth representation
• geometry representation
• immersive video
• depth colorization