This paper presents a rate-distortion based selective decoding for pixel-domain distributedvideo compression (DVC) system. In the proposed system, the Wyner-Ziv frames are divided into several sub-images. Each of the...
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ISBN:
(纸本)9781424417650
This paper presents a rate-distortion based selective decoding for pixel-domain distributedvideo compression (DVC) system. In the proposed system, the Wyner-Ziv frames are divided into several sub-images. Each of these sub-images is encoded and decoded independently. At the decoder, the rate-distortion ratio is estimated for each bitplane of the sub-images. Only the bitplanes with high rate-distortion ratios are Turbo decoded. A minimum-distance symbol reconstruction is proposed to estimate the rest of the bitplanes by using the side information and Turbo-decoded bitplanes. More accurate placement of the parity bits results in an improved system performance, especially for video sequences with a relatively large static background. coding results and comparison with existing DVC schemes and with H.264 interframe coding are presented to illustrate the performance of the proposed system.
distributed video coding (DVC) displays promising performance at low spatial resolutions but begins to struggle as the resolution increases. One of the limiting aspects is its 4x4 block size of Discrete Cosine Transfo...
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ISBN:
(纸本)9781509059904
distributed video coding (DVC) displays promising performance at low spatial resolutions but begins to struggle as the resolution increases. One of the limiting aspects is its 4x4 block size of Discrete Cosine Transform (DCT) which is often impractical at higher resolutions. This paper investigates the impact of exploiting larger DCT block sizes on the performance of transform domain DVC at higher spatial resolutions. In order to utilize a larger block size in DVC, appropriate quantisers have to be selected and this has been solved by means of incorporating a content-aware quantisation mechanism to generate image specific quantisation matrix for any DCT block size. Experimental results confirm that the larger 8x8 block size consistently exhibit superior RD performance for CIF resolution sequences compared to the smaller 4x4 block sizes. Significant PSNR improvement has been observed for 16x16 block size at 4CIF resolution with up to 1.78dB average PSNR gain compared to its smaller block alternatives.
This paper presents a new approach to generate side information for distributed video coding (DVC) for wireless capsule endoscopy (WCE). WCE allowed facilitating the diagnosis;however, the problem of low energy limits...
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ISBN:
(纸本)9781479928903
This paper presents a new approach to generate side information for distributed video coding (DVC) for wireless capsule endoscopy (WCE). WCE allowed facilitating the diagnosis;however, the problem of low energy limits its image quality and duration of use. To reduce this problem, the proposed codec uses a database to generate side information (SI), by exploiting similarity in human anatomy rather than motion compensation. The first test results prove the feasibility of this technique and show good compression and good image quality compared to JPEG.
This work aims at improving the quality of the side information in distributed video coding. Based on genetic algorithms, our proposed technique combines several frames, interpolated using previously developed methods...
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ISBN:
(纸本)9781424456536
This work aims at improving the quality of the side information in distributed video coding. Based on genetic algorithms, our proposed technique combines several frames, interpolated using previously developed methods, in a fusion-based approach. Simulation results show a significant improvement in the side information quality compared to other interpolation techniques available in the literature, which greatly improves the rate-distortion performance of a distributedvideo codec, where the gain in PSNR can reach 6dB.
distributed video coding (DVC) has recently been proposed for emerging scenarios, where sources of correlated video do not communicate, as in some video-surveillance applications, or to simplify the coder for video eq...
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ISBN:
(纸本)9781424414833
distributed video coding (DVC) has recently been proposed for emerging scenarios, where sources of correlated video do not communicate, as in some video-surveillance applications, or to simplify the coder for video equipment with power consumption constraints. In this paper we propose and compare different DVC schemes. In particular, we propose the use of the wavelet transform and analyze the performance of encoders based on turbo-codes and on a novel modulo-reduction procedure. The proposed schemes do not need feedback from the receiver and use statistical models for the estimation of the required bit-rate. Experimental results show that the proposed schemes have good performance when compared with Similar asymmetric video compression schemes, and that DVC can be an interesting option in appropriate scenarios.
A novel concept of channel division to improve the performance of distributed video coding is proposed in this work. At the decoder, the proposed algorithm partitions each side information frame into multiple regions ...
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ISBN:
(纸本)9781424456536
A novel concept of channel division to improve the performance of distributed video coding is proposed in this work. At the decoder, the proposed algorithm partitions each side information frame into multiple regions with different expected distortions. It is shown that the partitioning is equivalent to the division of the virtual noisy channel from the encoder to the decoder into multiple channels. Then, the proposed algorithm analyzes the noise characteristics of those multiple channels, and allocates a limited bit budget to those channels adaptively to improve the rate-distortion performance. Simulation results demonstrate that the proposed algorithm provides up to 5 dB better performance than the conventional DVC algorithms, as well as reduces the decoding complexity significantly.
in some videocoding applications, it is desirable to reduce the complexity of the video encoder at the expense of a more complex decoder. distributedvideo (DV) coding is a new paradigm that aims to achieve this. To ...
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ISBN:
(纸本)9781424407286
in some videocoding applications, it is desirable to reduce the complexity of the video encoder at the expense of a more complex decoder. distributedvideo (DV) coding is a new paradigm that aims to achieve this. To allocate a proper number of bits to each frame, most DV coding algorithms use a feedback channel (FBC). However, in some cases, a FBC does not exist. In this paper, we therefore propose a rate allocation (RA) algorithm for pixel-domain distributedvideo coders without FBC. Our algorithm estimates at the encoder the number of bits for every frame without significantly increasing the encoder complexity. Experimental results show that our RA algorithm delivers satisfactory estimates of the adequate encoding rate, especially for sequences with little motion.
distributed video coding (DVC) is a promising coding solution for some emerging applications, where the encoder complexity, power consumption or memory requirements are constraint the system resources. Current approac...
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ISBN:
(纸本)9783540771289
distributed video coding (DVC) is a promising coding solution for some emerging applications, where the encoder complexity, power consumption or memory requirements are constraint the system resources. Current approaches to DVC focus on improving the performance of the Wyner-Ziv coding by improving the quality of the reconstructed side information or by improving the quality of channel codes. Up to date, no attention has been paid to the problem of key frames coding where a low-encoding complexity scenario is also needed. This work focuses on key frames coding in its effect to the Wyner-Ziv frames decoding aiming to implement a very low-complexity Turbo Trellis Coded Modulation (TTCM) based DVC architecture. In this paper, we propose a new key frame coding scheme which has very low complexity and memory requirements for the TTCM based distributedvideo codec. Results show that the proposed intra frame codec for key frame coding outperforms the JPEG2000 and the Intra H.264 AVC codecs in terms of encoding-time and memory requirements, with better RD performance.
distributed video coding paradigm aims at transferring the major part of the processing computation effort from the encoder to the decoder. Motion interpolation is done at the decoder to generate side information (SI)...
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ISBN:
(纸本)9781467344050;9781467344067
distributed video coding paradigm aims at transferring the major part of the processing computation effort from the encoder to the decoder. Motion interpolation is done at the decoder to generate side information (SI) through motion compensated temporal interpolation (MCTI). SI is considered as a noisy version of the original data: channel control coding schemes, such as turbo coding, are used to eliminate the errors (SI inaccuracies). The video data is turbo encoded and the parity bits are sent to the decoder. The systematic bits, however, are discarded since the decoder already disposes of SI that can be used for the channel likelihood ratio calculations. However, when the MCTI generation of SI is highly corrupted, the channel likelihood ratios based on the SI are inefficient and even misleading. A number of parity bits number exceeding the original data length may then be required, thus leading to an undesirable expansion effect. In this paper, we propose a method to detect adaptively the situations where the SI is of lower quality. Then puncturing matrices, enabling systematic bits, are used to help computing reliable channel likelihood ratios. An improvement up to 0.5 dB is reported for PSNRs vs bit rate performances.
Side information(SI) generation is one of the key components of a Wyner-Ziv coder. In this paper we present a novel multi-frame SI generation approach which uses adaptive temporal filtering to estimate the pixel value...
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ISBN:
(纸本)9781424414369
Side information(SI) generation is one of the key components of a Wyner-Ziv coder. In this paper we present a novel multi-frame SI generation approach which uses adaptive temporal filtering to estimate the pixel values for SI and motion vector filtering for refinement. For temporal filtering, we derive the optimal mean squared error temporal filter when the noise can be evaluated, and propose a similarity weighted temporal filter when the knowledge of the noise is not available. The temporal filter adapts on the quality of the motion estimation. The quality of SI generation is further improved by using motion vector filtering to reduce the noise effect from motion estimation. Experimental results indicate that the proposed SI generation approach yields good performance in terms of SI quality and conditional entropy.
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