Title :
Colour space transforms for improved video compression
Author :
Yanxiang Wang ; Abhayaratne, Charith ; Weerakkody, Rajitha ; Mrak, Marta
Author_Institution :
Dept. of Electron. & Electr. Eng., Univ. of Sheffield, Sheffield, UK
Abstract :
The Version 1 of the latest video coding standard High Efficiency Video Coding (HEVC) supports 4:2:0 colour sampling and colour representation that includes a luminance and two chrominance colour bands. To enable efficient coding of content with 4:4:4 sampling format and RGB colour space some improvements to the coding pipeline are needed. This paper investigates methods for converting RGB colour space into a luminance and two chrominance colour space suitable for HEVC encoding. Four colour transform domains, namely, YCbCr, YCoCg, Karhunen-Loève Transform (KLT) and 3-point Pseudo Discrete Cosine Transform (P-DCT), are investigated for converting RGB into a colour space usable in HEVC range extension test model. One of the proposed approximations of KLT transform matrices results in overall highest BD-rate savings and BD-PSNR improvements.
Keywords :
Karhunen-Loeve transforms; data compression; discrete cosine transforms; image colour analysis; image representation; image sampling; video coding; 3-point pseudo discrete cosine transform; BD-PSNR; BD-rate savings; HEVC encoding; KL transform matrices; Karhunen-Loeve transform; P-DCT; RGB colour space; YCbCr; YCoCg; chrominance colour bands; chrominance colour space; coding pipeline; colour representation; colour sampling; colour space transforms; colour transform domains; high efficiency video coding; luminance; video coding standard; video compression; Color; Transforms; Transmission line matrix methods; Colour space transforms; DCT; HEVC; KLT; Lifting; Screen content;
Conference_Titel :
Systems, Signals and Image Processing (IWSSIP), 2014 International Conference on
Conference_Location :
Dubrovnik
