Title :
Improved weighted prediction based color gamut scalability in SHVC
Author :
Sansli, Done Bugdayci ; Aminlou, Alireza ; Ugur, Kemal ; Hannuksela, Miska M. ; Gabbouj, Moncef
Author_Institution :
Signal Process. Dept., Tampere Univ. of Technol., Tampere, Finland
Abstract :
One use case that the scalable extension (SHVC) of the state-of-the-art High Efficiency Video Coding (HEVC) standard aims for is to support Ultra High Definition (UHD) TV broadcast in a backwards compatible way with the existing High Definition (HD) TV broadcast. However, since UHD content typically has higher bit-depth and wider color gamut in addition to increased spatial resolution, the compression efficiency is highly affected by the inter-layer processing applied on the base layer picture. This paper proposes an improvement for the weighted prediction based color gamut scalability to have a better mapping between the color gamuts of the base and enhancement layers. The proposed method aims at capturing the nonlinear characteristics of the color gamut mapping using a piecewise linear model, whose parameters are signaled through weighted prediction mechanism and multiple inter-layer reference pictures. Compared to other existing methods for color gamut mapping in SHVC, such as the 3D Look Up Table (LUT) method, the proposed weighted prediction based approach is less complex, as it does not require any changes to the decoder. The simulation results show up to 3.8% Bjontegaard delta bitrate gain in luma for all intra and 3.0% for random access configurations compared to the existing weighted prediction based scalability method in SHVC.
Keywords :
image colour analysis; image segmentation; piecewise linear techniques; video coding; HEVC standard; SHVC; UHD TV broadcast; base layer picture; bit-depth; color gamut mapping; compression efficiency; high efficiency video coding standard; interlayer processing; multiple interlayer reference pictures; piecewise linear model; random access configurations; scalable extension; spatial resolution; ultra high definition TV broadcast; weighted prediction based color gamut scalability; weighted prediction mechanism; Color; Decoding; High definition video; Image color analysis; Predictive models; Scalability; Video coding; BT.2020; BT.709; HEVC; SHVC; scalable video coding; weighted prediction; wide color gamut;
Conference_Titel :
Visual Communications and Image Processing Conference, 2014 IEEE
DOI :
10.1109/VCIP.2014.7051539