Two-Layer Coding for High Dynamic Range Images Based on Histogram Sparsity

2019 Fiscal Year Final Research Report

• Project/Area Number: 16K18104
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Communication/Network engineering
• Research Institution: The University of Electro-Communications (2017-2019); Nagaoka University of Technology (2016)
• Principal Investigator: Yoshida Taichi 電気通信大学, 大学院情報理工学研究科, 助教 (60737914)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: HDR画像符号化 / 二階層符号化 / ロスレス符号化 / トーンマッピング / 画像デノイズ

Outline of Final Research Achievements

In this research, techniques are proposed for two-layer coding of high dynamic range (HDR) images. The two-layer coding is applied by JPEG XT that is a recent global standard of HDR image coding. The proposed techniques improve compression rates for the two-layer coding as fundamentals and are selectively used without interfering other fundamental ones. They are realized based on the particular property of HDR images and their two-layer coding that is introduced in this research. Therefore, this research contributes the next global standard for HDR image coding. In simulation, they show the improvement of compression rates, which reaches up to 15%, compared with methods without themselves.

Free Research Field

信号処理, 画像処理

Academic Significance and Societal Importance of the Research Achievements

本研究成果は，HDR画像の二階層符号化において圧縮率向上に寄与する複数の知見を提供しておりその点で意義がある．本研究では，圧縮率向上に寄与するHDR画像の特性や二階層符号化の特徴などを発見するとともに，二階層符号化でそれらを用いるアルゴリズムを提案した．近年の符号化では，他要素技術を害さない圧縮率向上に寄与する要素技術を複数組み合わせて高圧縮を達成するのが主流である．本研究の知見は，その要素技術に成り得るものであり，二階層符号化の発展に貢献している．