DocumentCode :
1757125
Title :
Visually Favorable Tone-Mapping With High Compression Performance in Bit-Depth Scalable Video Coding
Author :
Zicong Mai ; Mansour, Hassan ; Nasiopoulos, Panos ; Ward, Rabab K.
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of British Columbia, Vancouver, BC, Canada
Volume :
15
Issue :
7
fYear :
2013
fDate :
Nov. 2013
Firstpage :
1503
Lastpage :
1518
Abstract :
In bit-depth scalable video coding, the tone-mapping scheme used to convert high-bit-depth to eight-bit videos is an essential yet very often ignored component. In this paper, we demonstrate that an appropriate choice of a tone-mapping operator can improve the coding efficiency of bit-depth scalable encoders. We present a new tone-mapping scheme that delivers superior compression efficiency while adhering to a predefined base layer perceptual quality. We develop numerical models that estimate the base layer bit-rate (Rb), the enhancement layer bitrate (Re), and the mismatch (QL) between the resulting low dynamic range (LDR) base-layer signal and the predefined base layer representation. Our proposed tone curve is given by the solution of an optimization problem which minimizes a weighted sum of Rb, Re, and QL. The problem formulation also considers the temporal effect of tone-mapping by adding a constraint to the optimization problem that suppresses flickering artifacts. We also propose a technique with which to tone-map a high-bit-depth video directly in a compression-friendly color space (e.g., one luma and two chroma channels) without converting to the RGB domain. Experimental results show that we can save up to 40% of the total bit-rate (or 3.5 dB PSNR improvement for the same bitrate), and, in general, about 20% bit-rate savings can be achieved.
Keywords :
data compression; image colour analysis; image representation; minimisation; numerical analysis; video coding; LDR base-layer signal; PSNR improvement; QL; Rb; Re; RGB domain; base layer bit-rate estimation; base layer perceptual quality; bit-depth scalable encoders; bit-rate savings; coding efficiency improvement; compression-friendly color space; develop; eight-bit videos; enhancement layer bitrate; flickering artifact suppression; high-bit-depth scalable video coding; high-bit-depth videos; high-compression performance; low-dynamic range base-layer signal; numerical models; one-luma channel; optimization problem; predefined base layer representation; quality mismatch; temporal effect; tone curve; tone-mapping operator; tone-mapping scheme; total bit-rate; two-chroma channel; Bit-depth scalable; HDR video compression; high dynamic range imaging; tone-mapping;
fLanguage :
English
Journal_Title :
Multimedia, IEEE Transactions on
Publisher :
ieee
ISSN :
1520-9210
Type :
jour
DOI :
10.1109/TMM.2013.2266633
Filename :
6525395
Link To Document :
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