DocumentCode :
75171
Title :
Improved Method to Select the Lagrange Multiplier for Rate-Distortion Based Motion Estimation in Video Coding
Author :
Gonzalez-de-Suso, Jose Luis ; Jimenez-Moreno, Amaya ; Martinez-Enriquez, Eduardo ; Diaz-de-Maria, Fernando
Author_Institution :
Dept. of Signal Theor. & Commun., Carlos III Univ. of Madrid, Getafe, Spain
Volume :
24
Issue :
3
fYear :
2014
fDate :
Mar-14
Firstpage :
452
Lastpage :
464
Abstract :
The motion estimation (ME) process used in the H.264/AVC reference software is based on minimizing a cost function that involves two terms (distortion and rate) that are properly balanced through a Lagrangian parameter, usually denoted as λmotion. In this paper we propose an algorithm to improve the conventional way of estimating λmotion and, consequently, the ME process. First, we show that the conventional estimation of λmotion turns out to be significantly less accurate when ME-compromising events, which make the ME process to perform poorly, happen. Second, with the aim of improving the coding efficiency in these cases, an efficient algorithm is proposed that allows the encoder to choose between three different values of λmotion for the Inter 16x16 partition size. To be more precise, for this partition size, the proposed algorithm allows the encoder to additionally test λmotion=0 and λmotion arbitrarily large, which corresponds to minimum distortion and minimum rate solutions, respectively. By testing these two extreme values, the algorithm avoids making large ME errors. The experimental results on video segments exhibiting this type of ME-compromising events reveal an average rate reduction of 2.20% for the same coding quality with respect to the JM15.1 reference software of H.264/AVC. The algorithm has been also tested in comparison with a state-of-the-art algorithm called context adaptive Lagrange multiplier. Additionally, two illustrative examples of the subjective performance improvement are provided.
Keywords :
image segmentation; motion estimation; video coding; H.264/AVC reference software; Lagrangian parameter; ME errors; ME process; coding quality; context adaptive Lagrange multiplier; motion estimation; rate distortion; video coding; video segmentation; Encoding; Estimation; Motion segmentation; Optimization; Software; Standards; Video coding; H264/Advanced Video Coding (AVC); Lagrange multiplier; motion estimation; rate-distortion optimization; video coding;
fLanguage :
English
Journal_Title :
Circuits and Systems for Video Technology, IEEE Transactions on
Publisher :
ieee
ISSN :
1051-8215
Type :
jour
DOI :
10.1109/TCSVT.2013.2276857
Filename :
6576132
Link To Document :
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