Journal of Applied Sciences ›› 2017, Vol. 35 ›› Issue (3): 355-365.doi: 10.3969/j.issn.0255-8297.2017.03.009

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Improvement for R-Lambda Rate Control Model

WANG Peng, NI Cui, ZHANG Guang-yuan, LI Ke-feng   

  1. School of Information Science and Electric Engineering, Shandong Jiaotong University, Jinan 250357, China
  • Received:2016-04-06 Revised:2016-08-11 Online:2017-05-30 Published:2017-05-30

Abstract:

In the reference code of high efciency video coding, the R-Lambda model is often used for rate control. However, the rate-Lambda (R-Lambda) allocates too much target bits to I-frames, causing serious quality decline in the following frames. To solve the problem, improvement for the R-Lambda model is proposed in this paper. An I-frame is segmented into motion regions, texture-rich regions and smooth regions according to the motion characteristics and complexity. The target bits are allocated to different regions based on the characteristics of human vision system. More target bits are allocated to the visual sensitive regions, and fewer allocated to the visual non-sensitive regions. Finally, the R-Lambda model is used to calculate quantization parameter (QP). Experimental results show that the proposed algorithm can guarantee uniformity of subjective quality, and improve overall quality of the reconstructed frames.

Key words: region classifcation, R-Lambda model, target bit, reconstructed quality

CLC Number: