Fast 3D-HEVC Depth Intra Coding Based on Boundary Continuity

Mei-Juan Chen,Lih-Jen Kau,Jie-Ru Lin,Yu-Chih Hsu,Yi-Sheng Ciou,Chia-Hung Yeh,Chuan-Yu Chang,Min-Hui Lin

doi:10.1109/access.2021.3083498

Abstract

The encoding format of the 3D extension of high efficiency video coding (3D-HEVC) consists of a multiview color texture and an associated depth map. Because of the unique characteristics of the depth map, advanced coding techniques are designed for depth map coding at the expense of computational complexity. In this paper, fast algorithms are conceived to accelerate the intra coding time of the depth map based on boundary continuity. First, the proposed fast prediction unit (PU) mode decision reduces the number of conventional intra prediction modes based on calculating the total sum of squares (TSS) of the PU boundaries. Second, the proposed fast depth modeling mode (DMM) decision makes use of the variances of the boundary pixels to determine the execution of the DMM. Third, the proposed coding unit (CU) early termination algorithm decides whether to further split the current CU by utilizing the thresholds of the TSS and the rate-distortion cost (RD-cost). The experimental results show that the proposed algorithm provides better performance in terms of coding speed and bitrate than the algorithm in previous work. The coding time of the depth map is reduced by 56.08%, while the Bjontegaard delta bitrate (BD-BR) is only increased by 0.32% for the synthesis view.

Highlights

With the requirement of video applications, video technology has become increasingly advanced in recent years. 3D videos have the ability to provide users with fantastic experiences in a stereoscopic world
Advanced techniques for depth map coding bring about additional computational complexity
We accelerate the depth map intra coding of 3D extension of high efficiency video coding (3D-high efficiency video coding (HEVC)) based on boundary continuity

Summary

Introduction

With the requirement of video applications, video technology has become increasingly advanced in recent years. 3D videos have the ability to provide users with fantastic experiences in a stereoscopic world. The depth map in the 3D-HEVC system has some features, The associate editor coordinating the review of this manuscript and approving it for publication was Charith Abhayaratne. Such as large amounts of smooth regions and sharp edges, which are totally different from each other in terms of color texture. The conventional HEVC encoders may not always maintain good coding efficiency when encoding depth maps that consist of smooth regions or edges. For this reason, new coding tools have been created for depth map coding, such as the depth modeling mode (DMM) [6] and depth intra skip (DIS) [7].

Objectives

Methods

Results

Conclusion