This paper presents a new framework for adaptive temporal filtering in wavelet interframe codecs, called the unconstrained motion compensated temporal filtering (UMCTF). This framework allows flexible and efficient te...
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This paper presents a new framework for adaptive temporal filtering in wavelet interframe codecs, called the unconstrained motion compensated temporal filtering (UMCTF). This framework allows flexible and efficient temporal filtering by combining the best features of motion compensation, used in predictive coding, with the advantages of interframe scalable wavelet video coding schemes. UMCTF provides higher coding efficiency, improved visual quality and flexibility of temporal and spatial scalability, higher coding efficiency and tower decoding delay than conventional MCTF schemes. Furthermore, UMCTF can also be employed in alternative open-loop scalable coding frameworks using DCT for the texture coding.
The paper presents a new framework for adaptive temporal filtering in wavelet interframe codecs, called unconstrained motion compensated temporal filtering (UMCTF). This framework allows flexible and efficient tempora...
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The paper presents a new framework for adaptive temporal filtering in wavelet interframe codecs, called unconstrained motion compensated temporal filtering (UMCTF). This framework allows flexible and efficient temporal filtering by combining the best features of motion compensation, used in predictive coding, with the advantages of interframe scalable wavelet video coding schemes. UMCTF provides higher coding efficiency, improved visual quality and flexibility of temporal and spatial scalability, higher coding efficiency and lower decoding delay than conventional MCTF schemes. Furthermore, UMCTF can also be employed in alternative open-loop scalable coding frameworks using DCT for the texture coding.
A commonly encountered problem in the communication of predictively encoded video is that of predictive mismatch or drift. The problem of predictive mismatch manifests itself in numerous communication scenarios, inclu...
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A commonly encountered problem in the communication of predictively encoded video is that of predictive mismatch or drift. The problem of predictive mismatch manifests itself in numerous communication scenarios, including on-demand streaming, real-time streaming and multicast streaming. This paper proposes a state-free video encoding architecture that alleviates this problem. The main benefit of state-free encoding is that there is no need for the encoder and the decoder to maintain the same state, or equivalently, predict using the same predictor. This facilitates robust communication of causally encoded media. The proposed approach is based on the Wyner-Ziv theorem in information theory. Consequently, it leverages the superior performance of coset codes for the Wyner-Ziv problem for predictive coding. A video codec, with state-free functionality, based on the H.26L encoding standard is proposed. The performance of the proposed codec is within 1-2.5 dB of the H.26L encoder.
The concept of drift compensation has been proposed to alleviate the propagation of visual distortions between successive video frames, which exists as a result of embedding watermarks in the compressed domain without...
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The concept of drift compensation has been proposed to alleviate the propagation of visual distortions between successive video frames, which exists as a result of embedding watermarks in the compressed domain without re-performing motion prediction. By viewing the drift compensation data as watermark signals with inverse polarity, we propose to enhance the blind watermark retrieval of drift-compensated watermarked MPEG video by appropriately de-spreading the drift compensation data and adding the resultant correlation output to the usual watermark correlation sum. In our experiments, spread spectrum watermarks with additive and multiplicative embedding for MPEG video are used. The results show that the proposed technique is indeed capable of improving the reliability of the estimated watermark for different videos compressed at different bit rates. The proposed idea is expected to be applicable to any image and video compression formats with predictive coding, including MPEG-1, MPEG-2, MPEG-4, H.261, or H.263.
In current interframe video compression systems, the encoder performs predictive coding to exploit the similarities of successive frames. The Wyner-Ziv theorem on source coding with side information available only at ...
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In current interframe video compression systems, the encoder performs predictive coding to exploit the similarities of successive frames. The Wyner-Ziv theorem on source coding with side information available only at the decoder suggests that an asymmetric video codec, where individual frames are encoded separately, but decoded conditionally (given temporally adjacent frames) achieves similar efficiency. We report results on a Wyner-Ziv coding scheme for motion video that uses intraframe encoding, but interframe decoding. In the proposed system, key frames are compressed by a conventional intraframe codec and in-between frames are encoded using a Wyner-Ziv intraframe coder. The decoder uses previously reconstructed frames to generate side information for interframe decoding of the Wyner-Ziv frames.
The three-step search algorithm has been widely used in block matching motion estimation due to its simplicity and effectiveness. The sparsely distributed checking points pattern in the first step is very suitable for...
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ISBN:
(纸本)0780376633
The three-step search algorithm has been widely used in block matching motion estimation due to its simplicity and effectiveness. The sparsely distributed checking points pattern in the first step is very suitable for searching large motion. However, for quasi-stationary blocks it will easily lead the search to be trapped into a local minimum. In this paper we propose a modification on the three-step search algorithm which employs a small diamond pattern in the first step, and the unrestricted search step is used to search the center area. Experimental results show that the proposed algorithm performs better than new three-step search in terms of MSE and requires less computation by up to 15% on average.
In this paper we propose a traffic model for delivering scalable video encoded with multiple layers on heterogeneous networks. The model is based on Markovian arrival process with marked transitions. The state of the ...
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In this paper we propose a traffic model for delivering scalable video encoded with multiple layers on heterogeneous networks. The model is based on Markovian arrival process with marked transitions. The state of the underlying Markov chain of the video arrival process is derived from the correlation feature found in the video data. The base layer and enhancement layer video frame size pairs are decided by a cluster detection algorithm; each cluster corresponds to one state of the Markov chain. The joint base and enhancement layer video frame size distribution for each state of the Markov chain is approximated by multivariate normal distribution. Simulation study on the traffic model data and the video trace data is carried out and compared with the model. The results show that the proposed traffic model can predict the network performance with good accuracy.
In this paper, an improved lattice filter structure is presented to model a two-dimensional (2-D) signal such as an image. The proposed structure generates a forward and a backward prediction error field at each stage...
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In this paper, an improved lattice filter structure is presented to model a two-dimensional (2-D) signal such as an image. The proposed structure generates a forward and a backward prediction error field at each stage of lattice structure, unlike other lattice structures [S.R. Parker et al., 1984][N. Tulu Onuk et al., 1994] wherein three or more backward prediction error fields are generated at each stage. This method is computationally efficient and possesses all the advantages of lattice algorithm. Simulation results show that the proposed lattice method results in better compression with lower computational cost than other lattice methods in literature [H.K. Kwan et al., 2001].
In this paper, we propose an algorithm, which allows for embedded coding in L/sub /spl infin// sense, i.e., progressive near-lossless as well as lossless image compression. The method is based on a lossy plus near-los...
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In this paper, we propose an algorithm, which allows for embedded coding in L/sub /spl infin// sense, i.e., progressive near-lossless as well as lossless image compression. The method is based on a lossy plus near-lossless refinement layered compression scheme. As a basis for the lossy layer we use the JPEG2000 standard. We show that this approach allows for a better image quality and compression performance for large tolerance values than algorithms based on predictive coding. The compression performance of the algorithm in the lossless mode is about the same as that of the JPEG2000 standard. Another advantage of this technique is that it allows for all the benefits and functionality of the lossy compression algorithm (JPEG2000) at low bit rates.
Unconstrained motion compensated temporal filtering (UMCTF) is a very general and flexible framework for temporal filtering. It allows the selection of many different filters as well as decomposition structures to all...
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Unconstrained motion compensated temporal filtering (UMCTF) is a very general and flexible framework for temporal filtering. It allows the selection of many different filters as well as decomposition structures to allow easy adaptation to video content, bandwidth variations, complexity requirements, and in conjunction with embedded coding can provide spatio-temporal-SNR scalability. In this paper we demonstrate the content-adaptive filter selection provided within the UMCTF framework. We show improvements in coding efficiency as well as in decoded visual quality using content-adaptive filters, at different granularities.
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