Compressed sensing (CS) is a new technique for simultaneous data sampling and compression. In this paper, we propose a new videocoding algorithm based on distributed Compressive Sampling(DCS) principles, where almost...
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ISBN:
(纸本)9781627485852
Compressed sensing (CS) is a new technique for simultaneous data sampling and compression. In this paper, we propose a new videocoding algorithm based on distributed Compressive Sampling(DCS) principles, where almost all computation burdens can be shifted to the decoder, resulting in a very low-complexity encoder. At the decoder, compressed video can be efficiently reconstructed. Our algorithm can be useful in those video applications that require very low complex encoders. Simulation results show that our scheme compares favorably with existing schemes at a much lower implementation cost. (C) 2011 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of Harbin University of Science and Technology
distributed video coding (DVC) is an emerging coding paradigm, aiming at low complexity encoders. This paper proposes a new scheme for transform domain Wyner-Ziv (WZ) video codec, where the key and WZ frames are encod...
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ISBN:
(纸本)9780769547299
distributed video coding (DVC) is an emerging coding paradigm, aiming at low complexity encoders. This paper proposes a new scheme for transform domain Wyner-Ziv (WZ) video codec, where the key and WZ frames are encoded in multiple layers. The layers of the each frame are generated by sub sampling the 4x4 blocks in the spatial domain. After decoding each layer, side information (SI) refinement process is employed to improve the quality of SI to decode the next WZ layer. The codec performance is further improved by the decoder-driven adaptive skip/WZ control, estimated using the refined SI and the correlation noise. Rate-Distortion performance of the proposed scheme is tested with several sequences and performance improvements are noted.
In this paper, we propose a region-adaptive quantization scheme and progressive side information/channel noise modeling for Wyner-Ziv videocoding. The proposed region-adaptive quantization scheme can enhance coding p...
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ISBN:
(纸本)9781424425907
In this paper, we propose a region-adaptive quantization scheme and progressive side information/channel noise modeling for Wyner-Ziv videocoding. The proposed region-adaptive quantization scheme can enhance coding performance and provide an additional functionality of region of interest (ROI) coding. It also improves the accuracy of channel noise modeling by using previously decoded bit-plane information. Simulation results show that the proposed region-adaptive quantization scheme is especially suitable for static sequences, and the progressive side information/channel noise modeling works well in dynamic scenes.
Improving side information quality has been a research focus for distributed video coding in the last years However. without access to the current frame, the common used motion-compensated temporal interpolation (MCT)...
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ISBN:
(纸本)9783642104664
Improving side information quality has been a research focus for distributed video coding in the last years However. without access to the current frame, the common used motion-compensated temporal interpolation (MCT) in spatial domain at the DVC decoder meets a hard challenge This paper introduces a novel MCTI-ODWT algorithm to generate better side information frame, which utilizes overcomplete discrete wavelet transform (ODWT) not only to reduce the noise caused by dense motion field error. but also to avoid the noise resulted from the sensitivity of high frequency components to the inaccurate motion vectors by using the mean square error of difference between the adjacent decoded frames as a judge of which subbands level MCTI is applied to The analysis and experimental results both show that the proposed algorithm is effective to produce better SI frame than MCTI in spatial domain with a gain up to 4dBs
distributed video coding (DVC) has been widely acclaimed as an emerging videocoding technology with immense potential for use in video surveillance systems due to its flexibility for designing extremely low complex v...
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ISBN:
(纸本)9781424428991
distributed video coding (DVC) has been widely acclaimed as an emerging videocoding technology with immense potential for use in video surveillance systems due to its flexibility for designing extremely low complex video encoders. In this paper, we propose a novel modified framework for the DVC codec considering a region-of-activity based coding algorithm. The frames will be split into a sequence of regions based on the activity level that reflect the error distribution in the side information. The macro blocks will be re-ordered to concatenate the unevenly distributed errors and form new blocks for turbo coding to improve the efficiency of the puncturing process. The performance of the proposed technique is verified for three standard test video sequences and up to 21% bit rate saving is demonstrated.
In this paper, we present an efficient side information extrapolation scheme with temporal and spatial consistency for low-delay Wyner-Ziv videocoding. Our method is based on the regularized local linear regression (...
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ISBN:
(纸本)9781424494743
In this paper, we present an efficient side information extrapolation scheme with temporal and spatial consistency for low-delay Wyner-Ziv videocoding. Our method is based on the regularized local linear regression (RLLR) model, in which each pixel in SI is approximated as a linear weighted combination of samples within a local temporal neighborhood. The optimal model parameters are estimated by projecting the transformation function onto the temporal training samples to exploit motion-related dependency. During this procedure, moving weights are incorporated into the objective function to express the relative importance of training samples in estimating parameters of the model. Furthermore, spatial correlation is explored by imposing an additional local smoothness penalty, which does good to estimate the occluded regions and complex motion regions. The learned function is smooth and locally linear, and can be obtained with a closed-form solution by solving a convex optimization problem. Experimental results demonstrate that the RLLR method achieves very competitive SI extrapolation performance compared with the state-of-the-art methods.
Source coding by exploiting the temporal and spatial correlations in an input video stream is well established in conventional videocoding. However, when distributed video coding (DVC) is concerned, shifting the sour...
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ISBN:
(纸本)9781424425709
Source coding by exploiting the temporal and spatial correlations in an input video stream is well established in conventional videocoding. However, when distributed video coding (DVC) is concerned, shifting the source coding from the encoder to the decoder made this a more complicated and possibly a sub optimal process. Exploiting the temporal correlations has so far been attempted utilizing the key frames, by motion compensation using the interpolated (or extrapolated) motion field. However, exploiting the spatial correlations within the DVC framework is still an unsolved problem. In this paper, we propose to exploit both spatial and temporal correlations to generate the side information at the decoder. The proposed architecture involves a bit plane level side information refinement mechanism extracting both temporal and spatial information available at the decoder. Simulation results show that, the proposed coding scheme can achieve about 40% bit rate saving over 3D refinement algorithm proposed in [1] which is utilized as the basis for implementing the proposed technique.
Research in distributed video coding for low complexity encoding has shown that without knowledge of the correlation between source and side information (i.e. the behavior of the dependency channel), the performance i...
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ISBN:
(纸本)9781424404810
Research in distributed video coding for low complexity encoding has shown that without knowledge of the correlation between source and side information (i.e. the behavior of the dependency channel), the performance is substantially below that of well known state-of-the-art video coders. In a practical system the decoder needs to estimate the statistics in this dependency channel. In this paper we investigate the relation between the compression ratio and the sensitivity of the estimated channel model parameter at the decoder side. We observe that this is a hard task, but not unrealistic. We show that the tolerable parameter range is very dependent on the compression ratio and the (actual) statistics in the dependency channel.
We propose the use of H.264 redundant slices for Systematic Lossy Error Protection (SLEP) of a video signal transmitted over an error-prone channel. In SLEP, the video signal is transmitted to the decoder without chan...
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ISBN:
(纸本)0819461172
We propose the use of H.264 redundant slices for Systematic Lossy Error Protection (SLEP) of a video signal transmitted over an error-prone channel. In SLEP, the video signal is transmitted to the decoder without channel coding. Additionally, a Wyner-Ziv encoded version of the video signal is transmitted in order to provide error-resilience. In the event of channel errors, the Wyner-Ziv description is decoded as a substitute for the error-prone portions of the primary video signal. Since the Wyner-Ziv description is typically coarser than the primary video signal, SLEP is a lossy error protection technique which trades-off residual quantization distortion for improved error-resilience properties, such as graceful degradation of decoder picture quality. We describe how H.264 redundant slices can be used to generate the Wyner-Ziv description, and present simulation results to demonstrate the advantages of this method over traditional methods such as FEC.
Motion estimation (ME) methods based on differential techniques provide useful information for video analysis, and moreover it is relatively easy to embed into them regularity constraints enforcing for example, contou...
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ISBN:
(纸本)9781424456536
Motion estimation (ME) methods based on differential techniques provide useful information for video analysis, and moreover it is relatively easy to embed into them regularity constraints enforcing for example, contour preservation. On the other hand, these techniques are rarely employed for video compression since, though accurate, the dense motion vector field (MVF) they produce requires too much coding resource and computational effort. However, this kind of algorithm could be useful in the framework of distributed video coding (DVC), where the motion vector are computed at the decoder side, so that no bit-rate is needed to transmit them. Moreover usually the decoder has enough computational power to face with the increased complexity of differential ME. In this paper we introduce a new image interpolation algorithm to be used in the context of DVC. This algorithm combines a popular DVC technique with differential ME. We adapt a pel-recursive differential ME algorithm to the DVC context;moreover we insert a regularity constraint which allows more consistent MVFs. The experimental results are encouraging: the quality of interpolated images is improved of up to 1.1 dB w.r.t. to state-of-the-art techniques. These results prove to be consistent when we use different GOP sizes.
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