文章基本信息

标题：スラント変換を用いたグラデーション領域に対する高画質符号化手法
本地全文：下载
作者：山田悦久 ; 山岸秀一 ; 美濃導彦等
期刊名称：映像情報メディア学会誌
印刷版ISSN：1342-6907
电子版ISSN：1881-6908
出版年度：2011
卷号：65
期号：11
页码：1594-1602
DOI：10.3169/itej.65.1594
出版社：The Institute of Image Information and Television Engineers
摘要：We propose a new coding method by applying slant transform (SLT) to gradation areas instead of discrete cosine transform (DCT). A contour in a gradation area, which is often caused by the coding process for high compression, is one of the typical artifact noises for subjective evaluation. Since the pixel value changes linearly in a gradation area, DCT is not always suitable for its transformation. In our proposed method, although only traditional DCT is utilized in the encoding process to avoid increasing computational complexity, the inverse SLT (ISLT) instead of IDCT is performed in the area that is estimated as a gradation area in accordance with the distribution of DCT coefficients in the decoding process. The coding block size of the gradation area is easily expanded by simple operations using the hierarchy of SLT. In accordance with our experimental analysis, the proposed scheme has been performed to clarify the improvement of quality in gradation areas.
关键词：画像符号化;スラント変換;DCT;グラデーション;高階調信号