Region-Based perceptual quality regulable bit allocation and rate control for video coding applications

2012 ◽  
Author(s):  
Guan-Lin Wu ◽  
Yu-Jie Fu ◽  
Shao-Yi Chien
Keyword(s):  
Video Coding ◽  
Rate Control ◽  
Bit Allocation ◽  
Perceptual Quality

scholarly journals Region-of-interest-based rate control scheme for high-efficiency video coding

2014 ◽  
Vol 3 ◽  
Author(s):  
Marwa Meddeb ◽  
Marco Cagnazzo ◽  
Béatrice Pesquet-Popescu
Keyword(s):  
Video Coding ◽  
Rate Control ◽  
Control Algorithm ◽  
High Efficiency ◽  
Region Of Interest ◽  
Bit Allocation ◽  
Bit Rate ◽  
High Efficiency Video Coding ◽  
Control Scheme ◽  
Rate Control Algorithm

This paper presents a novel rate control scheme designed for the newest high efficiency video coding (HEVC) standard, and aimed at enhancing the quality of regions of interest (ROI) for a videoconferencing system. It is designed to consider the different regions at both frame level and coding tree unit (CTU) level. The proposed approach allocates a higher bit rate to the region of interest while keeping the global bit rate close to the assigned target value. The ROIs, typically faces in this application, are automatically detected and each CTU is classified in a region of interest map. This binary map is given as input to the rate control algorithm and the bit allocation is made accordingly. The algorithm is tested, first, using the initial version of the controller introduced in HEVC test model (HM.10), then, extended in HM.13. In this work, we first investigate the impact of differentiated bit allocation between the two regions using a fixed bit rate ratio in intra-coded frames (I-frames) and Bidirectionally predicted frames (B-frames). Then, unit quantization parameters (QPs) are computed independently for CTUs of different regions. The proposed approach has been compared to the reference controller implemented in HM and to a ROI-based rate control algorithm initially proposed for H.264 that we adopted to HEVC and implemented in HM.9. Experimental results show that our scheme has comparable performances with the ROI-based controller proposed for H.264. It achieves accurate target bit rates and provides an improvement in region of interest quality, both in objective metrics (up to 2 dB in PSNR) and based on subjective quality evaluation.

scholarly journals A Novel Two-Level Rate Control Algorithm Based on Visual Attention for 360-Degree Video for Versatile Video Coding Standard

2020 ◽  
Author(s):  
Hoda Roodaki
Keyword(s):  
Visual Attention ◽  
Video Coding ◽  
Rate Control ◽  
Control Algorithm ◽  
Perceptual Quality ◽  
Motion Models ◽  
Proper Number ◽  
Rate Control Algorithm ◽  
Motion Complexity

Abstract 360-degree video is providing users with an interactive experience to explore the scenes freely. But, because only a small portion of the entire video, called viewport, is watched at every point in time, transmitting the entire video is bandwidth-consuming. Since, the perceptual quality of such video mainly depends on the quality of the viewport, more bandwidth should be assigned to these important parts of the scene. Hence, understanding how people observe and explore 360-degree content is essential. In this paper, we propose a new Two-level rate control algorithm which tries to allocate more bits for encoding the viewport parts of a 360-degree video. The head and eye movements of the observers is used to investigate the visual attention of people to detect the viewports. Then, a Coding Tree Unit (CTU) level rate assignment approach is proposed to assign a proper number of bits to each CTU of the viewport and non-viewport parts. It is assumed that higher motion complexity results in higher bitrates of the encoded video. So, we propose to assign the proper number of bits to each CTU according to its motion complexity. Another novel part of our proposed approach is proposing a new metric to parameterize the motion complexity of each CTU using the high-order motion models in Versatile Video Coding (VVC) standard. Experimental results show that our proposed rate control, on average, achieves 58.27% reduction in bitrate in the Bjøntegaard-Bitrate scales, compared to the standard VCC standard. Furthermore, the proposed scheme provides a significantly better subjective viewing quality compared to the-state-of-the-art methods.

A Novel Rate Control Algorithm for H.264/AVC Considering Frame Activity

2014 ◽  
Vol 543-547 ◽  
pp. 3096-3099
Author(s):  
Bo Tian ◽  
Yi Min Yang ◽  
Shu Ting Cai
Keyword(s):  
Video Coding ◽  
Rate Control ◽  
Control Algorithm ◽  
Video Quality ◽  
Bit Allocation ◽  
Video Sequences ◽  
Scene Change ◽  
Local Motion ◽  
Motion Activity ◽  
Rate Control Algorithm

Rate control has significant impact on the video coding. However, the conventional rate control algorithm in the latest video coding standard H.264 without take into account the human visual system and result in video quality fluctuation. To address this problem, we propose a novel rate control algorithm for H.264/AVC considering frame activity. First, a method is proposed to detect the scene change in frames of video sequences. Second, bit allocation to frame is related to the frame activity which is calculated on the local motion activity and scene change in frames. And in the MB level, the number of bits allocated to each MB is determined by its local motion activity. Experimental results show that the proposed rate control algorithm can increase average PSNR by 0.9137 comparisons with the JVT-G012, and reduces the bit-rate error by up to 0.06%.

Efficient Bit Allocation and Rate Control Algorithms for Hierarchical Video Coding

2010 ◽  
Vol 20 (9) ◽  
pp. 1210-1223 ◽  
Author(s):  
Chan-Won Seo ◽  
Jung Won Kang ◽  
Jong-Ki Han ◽  
Truong Q. Nguyen
Keyword(s):  
Video Coding ◽  
Rate Control ◽  
Bit Allocation ◽  
Control Algorithms
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