Popular video coding standards like H.264 and MPEG working on the principle of motion-compensated pre-dictive coding demand much of the computational resources at the encoder increasing its complexity. Such bulky enco...Popular video coding standards like H.264 and MPEG working on the principle of motion-compensated pre-dictive coding demand much of the computational resources at the encoder increasing its complexity. Such bulky encoders are not suitable for applications like wireless low power surveillance, multimedia sensor networks, wireless PC cameras, mobile camera phones etc. New video coding scheme based on the principle of distributed source coding is looked upon in this paper. This scheme supports a low complexity encoder, at the same time trying to achieve the rate distortion performance of conventional video codecs. Current im-plementation uses LDPC codes for syndrome coding.展开更多
In the frame of compressed sensing distributed video coding, the design of the quantization matrix directly affects the reconstruction quality of the receiving terminal of the video. In this article, we present a new ...In the frame of compressed sensing distributed video coding, the design of the quantization matrix directly affects the reconstruction quality of the receiving terminal of the video. In this article, we present a new design method of the Gaussian quantization matrix adapting to the compressed sensing coding, for that the distribution of the parameters of the image is featured of the characteristic of approximately normal distribution after measured by compressive sensing. By this way, the parameters of a certain quantity of the image frames depending on the video sequences generated by the Gaussian quantization matrix possess certain adaptive capacity. By comparison with the plan of the traditional quantization, the quantization matrix presented in this article would improve the reconstruction quality of the video.展开更多
In Wyner-Ziv (WZ) Distributed Video Coding (DVC), correlation noise model is often used to describe the error distribution between WZ frame and the side information. The accuracy of the model can influence the perform...In Wyner-Ziv (WZ) Distributed Video Coding (DVC), correlation noise model is often used to describe the error distribution between WZ frame and the side information. The accuracy of the model can influence the performance of the video coder directly. A mixture correlation noise model in Discrete Cosine Transform (DCT) domain for WZ video coding is established in this paper. Different correlation noise estimation method is used for direct current and alternating current coefficients. Parameter estimation method based on expectation maximization algorithm is used to estimate the Laplace distribution center of direct current frequency band and Mixture Laplace-Uniform Distribution Model (MLUDM) is established for alternating current coefficients. Experimental results suggest that the proposed mixture correlation noise model can describe the heavy tail and sudden change of the noise accurately at high rate and make significant improvement on the coding efficiency compared with the noise model presented by DIStributed COding for Video sERvices (DISCOVER).展开更多
In the Wyner-Ziv(WZ) video coding paradigm, a virtual correlation channel is assumed between the quantized source and the side information(SI) at the decoder, and channel coding is applied to achieve compression. In t...In the Wyner-Ziv(WZ) video coding paradigm, a virtual correlation channel is assumed between the quantized source and the side information(SI) at the decoder, and channel coding is applied to achieve compression. In this paper, errors caused by the virtual correlation channel are addressed and an error concealment approach is proposed for pixel-based WZ video coding. In the approach, errors after decoding are classified into two types. Type 1 errors are caused by residual bit errors after channel decoding, while type 2 errors are due to low quality of SI in part of a frame which causes SI not lying within the quantization bin of a decoded quantized pixel value. Two separate strategies are respectively designed to detect and conceal the two types of errors. Simulations are carried out and results are presented to demonstrate the effectiveness of the proposed approach.展开更多
The Wyner-Ziv distributed video coding scheme is characterized for its intraframe encoder and interframe decoder which can also approach the efficiency of an interframe encoder-decoder system. In Wyner-Ziv residual co...The Wyner-Ziv distributed video coding scheme is characterized for its intraframe encoder and interframe decoder which can also approach the efficiency of an interframe encoder-decoder system. In Wyner-Ziv residual coding of video, the residual of a frame with respect to a reference frame is Wyner-Ziv encoded, which can reduces the input entropy and leads to a higher coding efficiency than directly encoding the original frame. In this paper, we propose a new approach of residual coding combined with Region Of Interest (ROI) extraction. Experimental results show that, the proposed scheme achieves better rate-distortion performance compared to conventional Wyner-Ziv coding scheme.展开更多
Accumulated low density parity check (LDPCA) codec is proposed for DISCOVER project in distributed video coding (DVC), which offers flexible coding rate. Although it can use feedback channel to adapt the rate to t...Accumulated low density parity check (LDPCA) codec is proposed for DISCOVER project in distributed video coding (DVC), which offers flexible coding rate. Although it can use feedback channel to adapt the rate to the correlation of the video, but in real applications, using feedback channel can not always be possible. To solve this problem, some researchers proposed estimating the code rate at the encoder but the performance was not very good. Based on their researches, this paper considers the impact of convergence rate for iteration on rate estimate, which can be calculated using its check matrix. As a pilot study, this paper pays attention to the regular LDPCA codec. At the same time, it considers the impact of deviation in the estimated crossover probability, which gives some constraints to rate estimate. In the experiment, the proposed algorithm can improve the rate-distortion performance by up to 1 dB-1.2 dB.展开更多
Distributed video coding(DVC)is a new video coding architecture.Compared with traditional video coding schemes,DVC has a simple encoder and complex decoder,which makes it suitable for circumstances where the encoder e...Distributed video coding(DVC)is a new video coding architecture.Compared with traditional video coding schemes,DVC has a simple encoder and complex decoder,which makes it suitable for circumstances where the encoder equipments are simple but the decoder equipments are complex.Most of the existing DVC architectures use decoder rate allocation method with the help of feedback channel.According to the results of the current decoding round,the decoder informs the encoder by feedback channel whether more parity bits are needed.The use of feedback channel not only increases the system delay,but also limits the use of DVC to instances where there is no feedback channel.In this paper,we propose a novel encoder rate allocation method.First,the simple three-step motion estimation is introduced into the encoder to estimate the side information of the decoder,and then the number of parity bits the decoder needs for each bitplane is allocated at the encoder according to the difference of the estimated side information and the current Wyner-Ziv(WZ)frame.Experiment results indicate that the accuracy of the proposed method is 5.18%-52.93% higher than that of the method proposed by Morbee.展开更多
针对现有Laplacian模型不能精确描述相关噪声分布,分布式视频编码(Distributed Video Coding,DVC)的率失真性能改善非常有限,文中提出一种基于高斯混合模型的分布式视频编码方法.首先分析了WZ帧与相应边信息之间相关噪声的统计特征,发...针对现有Laplacian模型不能精确描述相关噪声分布,分布式视频编码(Distributed Video Coding,DVC)的率失真性能改善非常有限,文中提出一种基于高斯混合模型的分布式视频编码方法.首先分析了WZ帧与相应边信息之间相关噪声的统计特征,发现相关噪声信息的分布并不满足某种单峰分布,然后采用高斯混合模型(Gaussian Mixture Model,GMM)对噪声系数直方图进行拟合,提出基于样本特征的EM(Expectation Maximum)算法来估计模型参数.将提出的高斯混合相关噪声模型与相应的Laplacian模型进行比较,实验结果表明前者更能精确描述相关噪声的统计特征,基于该模型的DVC率失真性能优于基于Laplacian模型的DISCOVER方案,获得的平均增益接近1dB.展开更多
与传统视频编码方法相比,DVC(distributed video coding)在编码性能方面还存在着较大差距。边信息估计是其中的关键技术之一,在很大程度上决定着编码效率。为缩短性能差距,改善边信息估计效率,提出一种针对像素域Wyner-Ziv视频编码系统...与传统视频编码方法相比,DVC(distributed video coding)在编码性能方面还存在着较大差距。边信息估计是其中的关键技术之一,在很大程度上决定着编码效率。为缩短性能差距,改善边信息估计效率,提出一种针对像素域Wyner-Ziv视频编码系统的改进算法,在解码端改善了关键帧之间的运动矢量获取以及采用重叠块运动补偿来生成边信息。通过对大量测试序列的实验,验证了改进算法的率失真性能得到改善。展开更多
文摘Popular video coding standards like H.264 and MPEG working on the principle of motion-compensated pre-dictive coding demand much of the computational resources at the encoder increasing its complexity. Such bulky encoders are not suitable for applications like wireless low power surveillance, multimedia sensor networks, wireless PC cameras, mobile camera phones etc. New video coding scheme based on the principle of distributed source coding is looked upon in this paper. This scheme supports a low complexity encoder, at the same time trying to achieve the rate distortion performance of conventional video codecs. Current im-plementation uses LDPC codes for syndrome coding.
文摘In the frame of compressed sensing distributed video coding, the design of the quantization matrix directly affects the reconstruction quality of the receiving terminal of the video. In this article, we present a new design method of the Gaussian quantization matrix adapting to the compressed sensing coding, for that the distribution of the parameters of the image is featured of the characteristic of approximately normal distribution after measured by compressive sensing. By this way, the parameters of a certain quantity of the image frames depending on the video sequences generated by the Gaussian quantization matrix possess certain adaptive capacity. By comparison with the plan of the traditional quantization, the quantization matrix presented in this article would improve the reconstruction quality of the video.
基金Supported by the National Natural Science Foundation of China ( No. 60736043, 60672088) and the National Basic Research Program of China (No. 2009CB32005).
基金Supported by the National Natural Science Foundation of China (No.60672088, No.60736043) the National Basic Research Development Program of China (2009CB320905)
基金Supported by the National Natural Science Foundation of China (No. 61071091)Jiangsu Province Graduate Innovative Research Plan (CX07B_107Z)
文摘In Wyner-Ziv (WZ) Distributed Video Coding (DVC), correlation noise model is often used to describe the error distribution between WZ frame and the side information. The accuracy of the model can influence the performance of the video coder directly. A mixture correlation noise model in Discrete Cosine Transform (DCT) domain for WZ video coding is established in this paper. Different correlation noise estimation method is used for direct current and alternating current coefficients. Parameter estimation method based on expectation maximization algorithm is used to estimate the Laplace distribution center of direct current frequency band and Mixture Laplace-Uniform Distribution Model (MLUDM) is established for alternating current coefficients. Experimental results suggest that the proposed mixture correlation noise model can describe the heavy tail and sudden change of the noise accurately at high rate and make significant improvement on the coding efficiency compared with the noise model presented by DIStributed COding for Video sERvices (DISCOVER).
基金Supported by the National Science and Technology Major Project of China(No.2018ZX10734401-004)
文摘In the Wyner-Ziv(WZ) video coding paradigm, a virtual correlation channel is assumed between the quantized source and the side information(SI) at the decoder, and channel coding is applied to achieve compression. In this paper, errors caused by the virtual correlation channel are addressed and an error concealment approach is proposed for pixel-based WZ video coding. In the approach, errors after decoding are classified into two types. Type 1 errors are caused by residual bit errors after channel decoding, while type 2 errors are due to low quality of SI in part of a frame which causes SI not lying within the quantization bin of a decoded quantized pixel value. Two separate strategies are respectively designed to detect and conceal the two types of errors. Simulations are carried out and results are presented to demonstrate the effectiveness of the proposed approach.
基金Supported by National Natural Science Foundation of China(61170147) Major Cooperation Project of Production and College in Fujian Province(2012H61010016) Natural Science Foundation of Fujian Province(2013J01234)
基金Supported by the National Natural Science Foundation of China (No.61003236, 61171053, 61170065)the Doctoral Fund of Ministry of Education of China (No.20113223110002)the Natural Science Major Program for Colleges and Universities in Jiangsu Province(No.11KJA520001)
文摘The Wyner-Ziv distributed video coding scheme is characterized for its intraframe encoder and interframe decoder which can also approach the efficiency of an interframe encoder-decoder system. In Wyner-Ziv residual coding of video, the residual of a frame with respect to a reference frame is Wyner-Ziv encoded, which can reduces the input entropy and leads to a higher coding efficiency than directly encoding the original frame. In this paper, we propose a new approach of residual coding combined with Region Of Interest (ROI) extraction. Experimental results show that, the proposed scheme achieves better rate-distortion performance compared to conventional Wyner-Ziv coding scheme.
文摘Accumulated low density parity check (LDPCA) codec is proposed for DISCOVER project in distributed video coding (DVC), which offers flexible coding rate. Although it can use feedback channel to adapt the rate to the correlation of the video, but in real applications, using feedback channel can not always be possible. To solve this problem, some researchers proposed estimating the code rate at the encoder but the performance was not very good. Based on their researches, this paper considers the impact of convergence rate for iteration on rate estimate, which can be calculated using its check matrix. As a pilot study, this paper pays attention to the regular LDPCA codec. At the same time, it considers the impact of deviation in the estimated crossover probability, which gives some constraints to rate estimate. In the experiment, the proposed algorithm can improve the rate-distortion performance by up to 1 dB-1.2 dB.
基金supported by the Fundamental Research Funds for the Central Universities.
文摘Distributed video coding(DVC)is a new video coding architecture.Compared with traditional video coding schemes,DVC has a simple encoder and complex decoder,which makes it suitable for circumstances where the encoder equipments are simple but the decoder equipments are complex.Most of the existing DVC architectures use decoder rate allocation method with the help of feedback channel.According to the results of the current decoding round,the decoder informs the encoder by feedback channel whether more parity bits are needed.The use of feedback channel not only increases the system delay,but also limits the use of DVC to instances where there is no feedback channel.In this paper,we propose a novel encoder rate allocation method.First,the simple three-step motion estimation is introduced into the encoder to estimate the side information of the decoder,and then the number of parity bits the decoder needs for each bitplane is allocated at the encoder according to the difference of the estimated side information and the current Wyner-Ziv(WZ)frame.Experiment results indicate that the accuracy of the proposed method is 5.18%-52.93% higher than that of the method proposed by Morbee.
文摘与传统视频编码方法相比,DVC(distributed video coding)在编码性能方面还存在着较大差距。边信息估计是其中的关键技术之一,在很大程度上决定着编码效率。为缩短性能差距,改善边信息估计效率,提出一种针对像素域Wyner-Ziv视频编码系统的改进算法,在解码端改善了关键帧之间的运动矢量获取以及采用重叠块运动补偿来生成边信息。通过对大量测试序列的实验,验证了改进算法的率失真性能得到改善。