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Rate Control Algorithm of Wireless Video Based on Visual Saliency Map Model 认领 引用 被引量：2
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作者 阮若林 胡瑞敏 +1 位作者 李忠明 尹黎明 《China Communications》 SCIE CSCD 2011年第7期105-110,共6页
In order to further improve the efficiency of video compression, we introduce a perceptual characteristics of Human Visual System (HVS) to video coding, and propose a novel video coding rate control algorithm based on... In order to further improve the efficiency of video compression, we introduce a perceptual characteristics of Human Visual System (HVS) to video coding, and propose a novel video coding rate control algorithm based on human visual saliency model in H.264/AVC. Firstly, we modifie Itti's saliency model. Secondly, target bits of each frame are allocated through the correlation of saliency region between the current and previous frame, and the complexity of each MB is modified through the saliency value and its Mean Absolute Difference (MAD) value. Lastly, the algorithm was implemented in JVT JM12.2. Simulation results show that, comparing with traditional rate control algorithm, the proposed one can reduce the coding bit rate and improve the reconstructed video subjective quality, especially for visual saliency region. It is very suitable for wireless video transmission. 展开更多
关键词 human visual system saliency map model wireless video coding rate control H.264/AVC
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Efficient Rate Control Algorithm for Multi-view Video Coding 认领 引用 被引量：1
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作者 刘峰 熊婕 +1 位作者 范晶晶 林琼洁 《China Communications》 SCIE CSCD 2011年第3期83-89,共7页
Rate control is one of the key factors influencing the multi-view video transmission.However,there is not a rate control algorithm in the existing Joint Multi-view Video Coding Model.In this paper,an efficient rate co... Rate control is one of the key factors influencing the multi-view video transmission.However,there is not a rate control algorithm in the existing Joint Multi-view Video Coding Model.In this paper,an efficient rate control algorithm and a bit allocation strategy for multi-view video coding are proposed.In order to obtain the consistent view quality,a bit allocation model based on the Lagrange optimum algorithm is firstly proposed.Secondly,considering the encoding statistical characteristics of different view types,a view weighting factor is introduced,and it will help improve the precision of bit allocation among views.Compared with the fixed QP control strategy,experiment results show that the proposed algorithm can efficiently control the bit rate and obtain more consistent views,with video visual quality improved. 展开更多
关键词 rate control rate distortion bit allocation view weighting factor
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Efficient Rate Control for Motion JPEG2000 under Constraint Memory 认领 引用 被引量：1
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作者 杜伟娜 孙军 安克彬 《Journal of Shanghai Jiaotong university(Science)》 EI 2006年第1期9-13,共5页
Fine scalability can provide not only precise rate control for constant bitrate (CBR) traffic, but also accurate quality control for variable bitrate (VBR) traffic. Motion JPEG2000 is a codec that can provide fine sca... Fine scalability can provide not only precise rate control for constant bitrate (CBR) traffic, but also accurate quality control for variable bitrate (VBR) traffic. Motion JPEG2000 is a codec that can provide fine scalability with bitstreams. An efficient rate control approach utilizing a single buffer and two kinds of threshold for Motion JPEG2000 under resource constraint was proposed, which can offer good result in the constant quality video. 展开更多
关键词 rate control coding pass distortion Motion JPEG2000
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Thermodynamic Characteristic Study of a High-temperature Flow-rate Control Valve for Fuel Supply of Scramjet Engines 认领 引用 被引量：8
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作者 ZENG Wen TONG Zhizhong +2 位作者 LI Songjing LI Hongzhou ZHANG Liang 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2012年第4期559-565,共7页
Thermodynamic characteristics are of great importance for the performance of a high-temperature flow-rate control valve,as high-temperature environment may bring problems,such as blocking of spool and increasing of le... Thermodynamic characteristics are of great importance for the performance of a high-temperature flow-rate control valve,as high-temperature environment may bring problems,such as blocking of spool and increasing of leakage,to the valve.In this paper,a high-temperature flow-rate control valve,pilot-controlled by a pneumatic servo system is developed to control the fuel supply for scramjet engines.After introducing the construction and working principle,the thermodynamic mathematical models of the valve are built based on the heat transfer methods inside the valve.By using different boundary conditions,different methods of simulations are carried out and compared.The steady-state and transient temperature field distribution inside the valve body are predicted and temperatures at five interested points are measured.By comparing the simulation and experimental results,a reasonable 3D finite element analysis method is suggested to predict the thermodynamic characteristics of the high-temperature flow-rate control valve. 展开更多
关键词 thermodynamic characteristics flow-rate control valve scramjet engines fuel supply
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In-Network Puncturing for Delay-Efficient Rate Control of Distributed Video Coding in Wireless Video Sensor Networks 认领 引用 被引量：1
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作者 Zhang Haitao Ma Huadong 《China Communications》 SCIE CSCD 2012年第6期45-54,共10页
Wyner-Ziv Video Coding （WZVC） is considered as a promising video coding scheme for Wireless Video Sensor Networks （WVSNs） due to its high compression efficiency and error resilience functionalities, as well as its... Wyner-Ziv Video Coding （WZVC） is considered as a promising video coding scheme for Wireless Video Sensor Networks （WVSNs） due to its high compression efficiency and error resilience functionalities, as well as its low encoding complex- ity. To achieve a good Rate-Distortion （R-D） per- formance, the current WZVC paradi^prls usually a- dopt an end-to-end rate control scheme in which the decoder repeatedly requests the additional deco- ding data from the encoder for decoding Wyner-Ziv frames. Therefore, the waiting time of the additional decoding data is especially long in multihop WVSNs. In this paper, we propose a novel pro- gressive in-network rate control scheme for WZVC. The proposed in-network puncturing-based rate control scheme transfers the partial channel codes puncturing task from the encoder to the relay nodes. Then, the decoder can request the addition- al decoding data from the relay nodes instead of the encoder, and the total waiting time for deco- ding Wyner-Ziv frames is reduced consequently. Simulation results validate the proposed rate con- trol scheme. 展开更多
关键词 wireless video sensor networks dis-tributed video coding WZVC rate control delay-efficient
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An Improvement of MPEG-4 Rate Control Algorithm 认领 引用
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作者 鲁照华 李华 刘继兴 《Transactions of Tianjin University》 EI CAS 2005年第1期40-43,共4页
Frame skipping in low bit video coding could significantly reduce the visual quality of reconstructed video. At the same time, if the complexity of the video sequence remains high for a long period, then driving up th... Frame skipping in low bit video coding could significantly reduce the visual quality of reconstructed video. At the same time, if the complexity of the video sequence remains high for a long period, then driving up the long term average bit rate, the only resort of MPEG-4 Q2 rate control algorithm results in using a high quantization scale, which shows a poor visual quality of the reconstructed video. This paper analyzes the main causes of frame skipping in current MPEG-4 frame rate control scheme, and presents a new rate control algorithm based on the quadratic R-D model over a CBR channel. Key features of the present work are: 1) the bits allocated to each P-frame or B-frame are in proportion to its distance from the end of this GOP, i.e. more bits are allocated to the frames that are nearer to their reference Ⅰ-frame; 2) the target buffer level is changeable in the GOP, at the end of each GOP(five P-frames or B-frames), the target buffer level is linearly reduced from 1/2 to 1/4 of buffer size, to other frames, the target buffer level is set to 1/2 of buffer size; 3) a selective and judicious use of the reduced resolution mode, in addition to a modulation of the quantization scale parameter, is to control the average long term bit rate. Experimental results with different video sequences of varied complexity, encoded at low bit rates show better efficacy of the proposed algorithm than MPEG-4 Q2 rate control scheme, and the experimental results also show that the improved algorithm has significantly reduced the number of frame skipping, increased the overall PSNR, and improved the perceptual quality. 展开更多
关键词 MPEG-4 rate control reduced resolution frame skipping bit allocation
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A New MPEG-2 Rate Control Method Based on Model Classification 认领 引用
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作者 古继兴 郑世宝 +1 位作者 王嘉 孙军 《Journal of Shanghai Jiaotong university(Science)》 2004年第3期37-40,共4页
The paper proposed a new MPEG-2 rate control method that is based on model classification. The macro-blocks are classified according to their prediction errors, and different parameters are used in the rate-quantizati... The paper proposed a new MPEG-2 rate control method that is based on model classification. The macro-blocks are classified according to their prediction errors, and different parameters are used in the rate-quantization and distortion-quantization model. The different model parameters are calculated from the previous frame of the same type in the process of coding. These models are used to estimate the relations among rate, distortion and quantization of the current frame. Further steps, such as R-D optimization based quantization adjustment and smoothing of quantization of adjacent macroblocks, are used to improve the quality. The results of the experiments prove that the technique is effective and can be realized easily. The method presented in the paper can be a good way for MPEG rate control. 展开更多
关键词 rate control model classification macroblock
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A new method based on two freedom-degree PD-P flow rate controller for congestion control in computer networks 认领 引用
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作者 Shen Wei Feng Rui Shao Huihe 《High Technology Letters》 EI CAS 2005年第3期257-262,共6页
The rate-based feedback PD-P controller of two freedom-degrees is proposed for the congestion control in computer networks to improve the abilities against disturbance. Moreover, the Dahlin algorithm is used for setti... The rate-based feedback PD-P controller of two freedom-degrees is proposed for the congestion control in computer networks to improve the abilities against disturbance. Moreover, the Dahlin algorithm is used for setting the controller to overcome the adverse effect caused by the propagation delay effectively. The research results show that the proposed scheme not only can make sources respond to the changes of network state more quickly, but also has a good robustness against estimated error of the delay. Then the packet queue level in buffer will be stabilized on the set-point quickly, and the delay and its jitter of the packet queuing will also become smaller. Besides, the flexible bandwidth allotment can be obtained by setting the weight coefficients. 展开更多
关键词 computer networks flow rate control two freedom-degrees
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Fair rate control for wireless ad-hoc networks with time varying channel capacities 认领 引用
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作者 Meiqin TANG Kai MA Xinping GUAN 《控制理论与应用（英文版）》 2010年第1期69-74,共6页
We consider the problem of fair rate control for wireless ad-hoc networks with time varying channel capacities. The interaction between links in wireless ad-hoc networks introduces additional constraints on the flow r... We consider the problem of fair rate control for wireless ad-hoc networks with time varying channel capacities. The interaction between links in wireless ad-hoc networks introduces additional constraints on the flow rate. A primal-dual algorithm that guarantees fair rate control is proved to be trajectory stable. Various fairness indexes are obtained by choosing the specified form of the utility functions, and the numerical results validate the effectiveness of the proposed algorithm. 展开更多
关键词 Wireless ad-hoc networks Rate control Trajectory stability Fairness
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Model classification rate control algorithmfor video coding 认领 引用
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作者 古继兴 郑世宝 +1 位作者 王嘉 孙军 《Journal of Systems Engineering and Electronics》 2005年第3期494-497,共4页
A model classification rate control method for video coding is proposed. The macro-blocks are classified according to their prediction errors, and different parameters are used in the rate-quantization and distortion-... A model classification rate control method for video coding is proposed. The macro-blocks are classified according to their prediction errors, and different parameters are used in the rate-quantization and distortion-quantization model. The different model parameters are calculated from the previous frame of the same type in the process of coding. These models are used to estimate the relations among rate, distortion and quantization of the current frame. Further steps, such as R-D optimization based quantization adjustment and smoothing of quantization of adjacent macrobloeks, are used to improve the quality. The results of the experiments prove that the technique is effective and can be realized easily. The method presented in the paper can be a good way for MPEG and H. 264 rate control. 展开更多
关键词 rate control model classification macroblock
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A rate control approach to distributed source coding for interferential multispectral image compression 认领 引用
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作者 宋娟 Li Yunsong Wu Chengke Wang Yangli 《High Technology Letters》 EI CAS 2010年第2期133-137,共5页
Distributed source coding （DSC） is applied to interferential multispectral image compression owing to strong correlation among the image frames. Many DSC systems in the literature use feedback channel （FC） to cont... Distributed source coding （DSC） is applied to interferential multispectral image compression owing to strong correlation among the image frames. Many DSC systems in the literature use feedback channel （FC） to control rate at the decoder, which limits the application of DSC. Upon an analysis of the image data, a rate control approach is proposed to avoid FC. Low-complexity motion compensation is applied first to estimate side information at the encoder. Using a polynomial fitting method, a new mathematical model is then derived to estimate rate based on the correlation between the source and side information. The experimental results show that our estimated rate is a good approximation to the actual rate required by FC while incurring a little bit-rate overhead. Our compression scheme performs comparable with the FC based DSC system and outperforms JPEG2000 significantly. 展开更多
关键词 interferential multispectral image distributed source coding （DSC） rate control motion compensation polynomial fitting
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Adaptive rate control on wireless transcoder 认领 引用
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作者 Chen Xudong Zhu Qingxin Liao Yong Fu Qingyun Xiong Guangze 《Journal of Systems Engineering and Electronics》 SCIE EI 2007年第3期633-640,共8页
To guarantee the real-time transmission of a video stream, based on the stochastic optimal control method, a frame layer adaptive rate control algorithm for the wireless transcoder is proposed, which is capable of dyn... To guarantee the real-time transmission of a video stream, based on the stochastic optimal control method, a frame layer adaptive rate control algorithm for the wireless transcoder is proposed, which is capable of dynamically determining the transcoder＇s objective bit rate, according to the bandwidth variation of the wireless channel and the buffer occupancy. Then the transient performance, steady performance, and computational complexity of the algorithm are analyzed. Finally, the experiment results demonstrate that the algorithm can improve the synthetic performance of rate control through the compromise between the end-to-end delay and the playout quality. 展开更多
关键词 streaming media rate control transcoder wireless local area network H.264/AVC.
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An efficient rate control algorithm for JPEG2000 based on reverse order 认领 引用 被引量：1
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作者 A.Etesaminia A.H.Mazinan 《Journal of Central South University》 SCIE EI CAS CSCD 2017年第6期1396-1405,共10页
The JPEG2000 image compression standard is the powerful encoder which can provide phenomenal rate-control performance.The post-compression rate-distortion(PCRD)algorithm in JPEG2000 is not efficient.It requires encodi... The JPEG2000 image compression standard is the powerful encoder which can provide phenomenal rate-control performance.The post-compression rate-distortion(PCRD)algorithm in JPEG2000 is not efficient.It requires encoding all coding passes even though a large contribution of them will not be contained in the final code-stream.Tier-1 encoding in the JPEG2000 standard takes a significant amount of memory and coding time.In this work,a low-complexity rate distortion method for JPEG2000 is proposed.It is relied on a reverse order for the resolution levels and the coding passes.The proposed algorithm encodes only the coding passes contained in the final code-stream and it does not need any post compression rate control part.The computational complexity of proposed algorithm is negligible,making it suitable to compression and attaining a significant performance.Simulations results show that the proposed algorithm obtained the PSNR values are comparable with the optimal PCRD. 展开更多
关键词 image coding JPEG2000 post compression rate distortion(PCRD) rate control
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An Efficient Intra-Frame Rate Control Algorithm for H.264/AVC Video Coding 认领 引用 被引量：1
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作者 ZHAO Dandan ZHOU Yujie +1 位作者 WANG Dayong MAO Junfa 《Wuhan University Journal of Natural Sciences》 CAS 2012年第3期243-248,共6页
Intra-frame plays a significant role in improving video quality for rate control of H.264/AVC.In this paper,an efficient intra-frame rate control algorithm is proposed for H.264/AVC video coding.The proposed scheme ad... Intra-frame plays a significant role in improving video quality for rate control of H.264/AVC.In this paper,an efficient intra-frame rate control algorithm is proposed for H.264/AVC video coding.The proposed scheme adjusts the quantization parameter （QP） of intra-frame adaptively according to intra-frame buffer fullness ratio,current buffer fullness ratio,and skipped frame ratio.Experimental results demonstrate that for a set of typical testing sequences,the proposed scheme can obtain accurate target bit rate,better peak signal-to-noise ratio （PSNR） performance and reduce the number of skipped frames significantly,when compared with existing schemes.More importantly,the proposed scheme is very flexible for different initial QPs and target bits. 展开更多
关键词 H.264/AVC intra-frame rate control
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A rate control scheme for H.264 video under low bandwidth channel 认领 引用 被引量：11
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作者 YIN Ming WANG Hong-yuan 《Journal of Zhejiang University-SCIENCE A》 EI CAS 2006年第6期990-995,共6页
The dilemma of the quantization parameter (QP) being involved in both rate control and rate-distortion optimization (RDO) prevents using the traditional rate control scheme. Although some rate control schemes are prop... The dilemma of the quantization parameter (QP) being involved in both rate control and rate-distortion optimization (RDO) prevents using the traditional rate control scheme. Although some rate control schemes are proposed to circumvent the dilemma, the inaccurate prediction model and improper bit allocation deter H.264 application on low bandwidth channel. To resolve this issue, this paper proposes a novel rate control scheme by considering the macroblock (MB) encoding complexity variation and buffer variation and by exploiting the spatio-temporal correlation sufficiently well. Simulations showed that this scheme improves the perceptual quality of the pictures with similar or smaller PSNR deviations when compared to that of rate control in JVT-O016. 展开更多
关键词 Video coding H.264 Rate control HRD Bit allocation
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Macroblock-Level Rate Control Scheme for Video Encoders 认领 引用
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作者 董彧焘 方向忠 王辉 《Journal of Donghua University(English Edition)》 EI CAS 2008年第2期148-152,共5页
Rate control plays an important role in video coding. An algorithm is proposed by Tsai et al in which macroblock’s coding order is rearranged to improve the coding quality. However, the complexity is very high due to... Rate control plays an important role in video coding. An algorithm is proposed by Tsai et al in which macroblock’s coding order is rearranged to improve the coding quality. However, the complexity is very high due to the change of macroblock’s coding order. In this paper, a macroblocl-level rate control algorithm is proposed which recalculates the quantization parameter of each macroblock based on its significance. Simulation results show that the proposed algorithm not only achieves 0.1-0.6 dB in peak signal-to-noise ratio (PSNR) but also reduces 33%-55% total encoding time compared to Tsai’s algorithm. 展开更多
关键词 rate control macroblock-level quantization
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An Improved Frame-Layer Bit Allocation Scheme for H.264/AVC Rate Control 认领 引用
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作者 林贵旭 郑世宝 朱良家 《Journal of Shanghai Jiaotong university(Science)》 EI 2009年第2期143-148,共6页
In this paper,we aim at improving the video quality degradation due to high motions or scene changes. An improved frame-layer bit allocation scheme for H.264/AVC rate control is proposed.First,current frame is pre-enc... In this paper,we aim at improving the video quality degradation due to high motions or scene changes. An improved frame-layer bit allocation scheme for H.264/AVC rate control is proposed.First,current frame is pre-encoded in 16×16 modes with a fixed quantization parameter(QP).The frame coding complexity is then measured based on the resulting bits and peak signal-to-ratio(PSNR) in the pre-coding stage.Finally,a bit budget is calculated for current frame according to its coding complexity and inter-frame PSNR fluctuation,combined with the buffer status.Simulation results show that,in comparison with the H.264 adopted rate control scheme, our method is more efficient to suppress the sharp PSNR drops caused by high motions and scene changes.The visual quality variations in a sequence are also relieved. 展开更多
关键词 H.264/AVC rate control bit allocation quality degradation
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Improved Rate Control Using Statistical Information in Unit-Layer for H.264/AVC 认领 引用
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作者 Myoung-jin KIM Min-cheol HONG 《Journal of Measurement Science and Instrumentation》 CAS 2011年第3期256-259,共4页
The purpose of this paper is to improve allocation of the number of bits by estimating the target bits in H.264/AVC rate control.In the scheme,an enhancement method of the target unit-layer bit allocation is proposed,... The purpose of this paper is to improve allocation of the number of bits by estimating the target bits in H.264/AVC rate control.In the scheme,an enhancement method of the target unit-layer bit allocation is proposed,which uses a frame and unit complexity estimation to improve the existing mean absolute difference(MAD)complexity measurement.Using the statistical characteristics,we obtain change of occurrence bit about QP to apply the bit amount by QP from the video characteristics in the estimated bit amount of the current frame.Simulation results show that not only the proposed rate control scheme could achieve time saving of more than 99% over existing rate control algorithm,but also PSNR and bit rate were almost the same as the performance in all the sequences. 展开更多
关键词 bit rate control MAD unit-layer statistical information
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RATE CONTROL ALGORITHM FOR H.264 VIDEO ENCODER 认领 引用 被引量：5
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作者 Xue Jinzhu Shen Lansun 《Journal of Electronics(China)》 2003年第6期456-460,共5页
This letter proposes a rate control algorithm for H.264 video encoder, which is based on block activity and buffer state. Experimental results indicate that it has an excellent performance by providing much accurate b... This letter proposes a rate control algorithm for H.264 video encoder, which is based on block activity and buffer state. Experimental results indicate that it has an excellent performance by providing much accurate bit rate and better coding efficiency compared with H.264. The computational complexity of the algorithm is reduced by adopting a novel block activity description method using the Sum of Absolute Difference (SAD) of 16× 16 mode, and its robustness is enhanced by introducing a feedback circuit at frame layer. 展开更多
关键词 Rate control Video coding H.264
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An Improved Rate Control Method Based on Modification at Scene Change for H.264 认领 引用
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作者 RU Guobao GAO Wenli FU Jianfeng 《Wuhan University Journal of Natural Sciences》 CAS 2007年第6期1047-1050,共4页
This paper presents an improved rate control method for H.264. First, the scene changes are detected by the average absolute difference of the brightness histograms between the adjacent frames. Then, the bit allocatio... This paper presents an improved rate control method for H.264. First, the scene changes are detected by the average absolute difference of the brightness histograms between the adjacent frames. Then, the bit allocation and quantization parameters are adjusted, using a certain threshold. In addition, the calculation of the mean absolute difference （MAD） is modified in an alternative way, which makes the rate distortion optimization （RDO） more accurate. Extensive simulation results show that the proposed method, compared with G012, can improve the average peak signal-to-noise ratio （PSNR） and moderate the image quality. 展开更多
关键词 brightness histogram mean absolute difference （MAD） rate distortion optimization （RDO） rate control scene change
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