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Aggelos K Katsaggelos - One of the best experts on this subject based on the ideXlab platform.
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rate distortion optimized product code forward error correction for video transmission over ip based wireless networks
International Conference on Acoustics Speech and Signal Processing, 2004Co-Authors: Fan Zhai, Y Eisenberg, Thrasyvoulos N Pappas, Randall A Berry, Aggelos K KatsaggelosAbstract:The problem of encoding and transmitting a video sequence over an IP-based wireless network, consisting of both wired and wireless links, is addressed. To combat the different types of packet loss in the heterogeneous network, the use of a product code forward error correction (FEC) scheme capable of providing unequal error protection is considered. At the transport layer, Reed-Solomon (RS) coding is used to provide inter-packet protection. In addition, rate-compatible punctured convolutional (RCPC) coding is used at the link layer to provide unequal intra-packet protection. Optimal Bit Allocation is performed in a rate-distortion optimized joint source-channel coding and power Allocation framework to achieve the best video quality. Simulation results illustrate the advantage of the proposed product code FEC scheme over previously studied approaches.
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a review of the minimum maximum criterion for Optimal Bit Allocation among dependent quantizers
IEEE Transactions on Multimedia, 1999Co-Authors: G M Schuster, G Melnikov, Aggelos K KatsaggelosAbstract:In this paper, we review a general framework for the Optimal Bit Allocation among dependent quantizers based on the minimum maximum (MINMAX) distortion criterion. The pros and cons of this optimization criterion are discussed and compared to the well-known Lagrange multiplier method for the minimum average (MINAVE) distortion criterion. We argue that, in many applications, the MINMAX criterion is more appropriate than the more popular MINAVE criterion. We discuss the algorithms for solving the Optimal Bit Allocation problem among dependent quantizers for both criteria and highlight the similarities and differences. We point out that any problem which can be solved with the MINAVE criterion can also be solved with the MINMAX criterion, since both approaches are based on the same assumptions. We discuss uniqueness of the MINMAX solution and the way both criteria can be applied simultaneously within the same optimization framework. Furthermore, we show how the discussed MINMAX approach can be directly extended to result in the lexicographically Optimal solution. Finally, we apply the discussed MINMAX solution methods to still image compression, intermode frame compression of H.263, and shape coding applications.
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a theory for the Optimal Bit Allocation between displacement vector field and displaced frame difference
IEEE Journal on Selected Areas in Communications, 1997Co-Authors: G M Schuster, Aggelos K KatsaggelosAbstract:We address the fundamental problem of Optimally splitting a video sequence into two sources of information, the displaced frame difference (DFD) and the displacement vector field (DVF). We first consider the case of a lossless motion-compensated video coder (MCVC), and derive a general dynamic programming (DP) formulation which results in an Optimal tradeoff between the DVF and the DFD. We then consider the more important case of a lossy MCVC, and present an algorithm which solves the tradeoff between the rate and the distortion. This algorithm is based on the Lagrange multiplier method and the DP approach introduced for the lossless MCVC. We then present an H.263-based MCVC which uses the proposed Optimal Bit Allocation, and compare its results to H.263. As expected, the proposed coder is superior in the rate-distortion sense. In addition to this, it offers many advantages for a rate control scheme. The presented theory can be applied to build new Optimal coders, and to analyze the heuristics employed in existing coders. In fact, whenever one changes an existing coder, the proposed theory can be used to evaluate how the change affects its performance.
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Optimal Bit Allocation among dependent quantizers for the minimum maximum distortion criterion
International Conference on Acoustics Speech and Signal Processing, 1997Co-Authors: Guido M Schuster, Aggelos K KatsaggelosAbstract:In this paper we introduce an Optimal Bit Allocation scheme for dependent quantizers for the minimum maximum distortion criterion. First we show how minimizing the Bit rate for a given maximum distortion can be achieved in a dependent coding framework using dynamic programming (DP). Then we employ an iterative algorithm to minimize the maximum distortion for a given Bit rate, which invokes the DP scheme. We prove that it converges to the Optimal solution. Finally we present a comparison between the minimum total distortion criterion and the minimum maximum distortion criterion for the encoding of an H.263 Intra frame. In this comparison we also point out the similarities between the proposed minimum maximum distortion approach and the Lagrangian multiplier based minimum total distortion approach.
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a video compression scheme with Optimal Bit Allocation among segmentation motion and residual error
IEEE Transactions on Image Processing, 1997Co-Authors: G M Schuster, Aggelos K KatsaggelosAbstract:We present a theory for the Optimal Bit Allocation among quadtree (QT) segmentation, displacement vector field (DVF), and displaced frame difference (DFD). The theory is applicable to variable block size motion-compensated video coders (VBSMCVC), where the variable block sizes are encoded using the QT structure, the DVF is encoded by first-order differential pulse code modulation (DPCM), the DFD is encoded by a block-based scheme, and an additive distortion measure is employed. We derive an Optimal scanning path for a QT that is based on a Hilbert curve. We consider the case of a lossless VBSMCVC first, for which we develop the Optimal Bit Allocation algorithm using dynamic programming (DP). We then consider a lossy VBSMCVC, for which we use Lagrangian relaxation, and show how an iterative scheme, which employs the DP-based solution, can be used to find the Optimal solution. We finally present a VBSMCVC, which is based on the proposed theory, which employs a DCT-based DFD encoding scheme. We compare the proposed coder with H.263. The results show that it outperforms H.263 significantly in the rate distortion sense, as well as in the subjective sense.
Martin Vetterli - One of the best experts on this subject based on the ideXlab platform.
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Bit Allocation for dependent quantization with applications to multiresolution and mpeg video coders
IEEE Transactions on Image Processing, 1994Co-Authors: Kannan Ramchandran, Antonio Ortega, Martin VetterliAbstract:We address the problem of efficient Bit Allocation in a dependent coding environment. While Optimal Bit Allocation for independently coded signal blocks has been studied in the literature, we extend these techniques to the more general temporally and spatially dependent coding scenarios. Of particular interest are the topical MPEG video coder and multiresolution coders. Our approach uses an operational rate-distortion (R-D) framework for arBitrary quantizer sets. We show how a certain monotonicity property of the dependent R-D curves can be exploited in formulating fast ways to obtain Optimal and near-Optimal solutions. We illustrate the application of this property in specifying intelligent pruning conditions to eliminate subOptimal operating points for the MPEG Allocation problem, for which we also point out fast nearly-Optimal heuristics. Additionally, we formulate an efficient Allocation strategy for multiresolution coders, using the spatial pyramid coder as an example. We then extend this analysis to a spatio-temporal 3-D pyramidal coding scheme. We tackle the compatibility problem of optimizing full-resolution quality while simultaneously catering to subresolution Bit rate or quality constraints. We show how to obtain fast solutions that provide nearly Optimal (typically within 0.3 dB) full resolution quality while providing much better performance for the subresolution layer (typically 2-3 dB better than the full-resolution Optimal solution). >
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Bit Allocation for dependent quantization with applications to mpeg video coders
International Conference on Acoustics Speech and Signal Processing, 1993Co-Authors: Kannan Ramchandran, Antonio Ortega, Martin VetterliAbstract:The problem of efficient Bit Allocation in a dependent coding environment is addressed. Techniques of Optimal Bit Allocation for independently coded signal blocks are extended to the more general dependent coding scenarios. Of particular interest is the topical MPEG (Motion Picture Experts Group) video coder. It is shown how a certain monotonicity property of dependent operational rate-distortion (R-D) curves, verified through MPEG simulations, can be exploited in formulating fast ways to obtain Optimal and near-Optimal solutions (in the R-D sense) for the MPEG Bit Allocation problem. >
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comments on interpolative multiresolution coding of advanced television with compatible subchannels and reply and additional comments
IEEE Transactions on Circuits and Systems for Video Technology, 1992Co-Authors: T Naveen, John W. Woods, Martin Vetterli, Didier J LegallAbstract:Recently, Uz et al. (ibid., vol.1., no.1, p.86-99, 1991) analyzed the propagation of quantization noise in a pyramid (with feedback) and subband decomposition schemes. In this study each band was independently quantized by a scalar quantizer of equal step size. The resulting reconstruction error spectrum indicated that in both the pyramid (without feedback) and subband coding schemes, noise was building up in lower frequencies. The commenters show that a quantizer assignment method, using mean-square-error (MSE) Optimal Bit Allocation, avoids the problem. The authors argue that the problem is more involved than just MSE Optimal Bit Allocation, and that compatible coding was the focus, as well as guaranteed quality, effects of numerical computations, and perceptual effects. The commenters further support their argument. >
Xinhua Zhuang - One of the best experts on this subject based on the ideXlab platform.
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A NOVEL DATA REPRESENTATION STRATEGY FOR WAVELET IMAGE COMPRESSION
2008Co-Authors: Bingbing Chai, J Vass, Xinhua ZhuangAbstract:Recent success in wavelet image coding is mainly attributed to recognition of the importance of data organization and representation. Several very competitive wavelet coders have been developed, namely, Shapiro's embedded zerotree wavelets (EZW), Servetto et al.'s morphological representation of wavelet data (MRWD), and Said and Pearlman's set partitioning in hierarchical trees (SPIHT). In this paper, we develop a novel wavelet image coder called significance-linked connected component analysis (SLCCA) of wavelet coefficients that exploits both within-subband clustering of significant coefficients and cross-subband dependency in significant fields. Extensive computer experiments show that the proposed SLCCA outperforms all three aforementioned wavelet coders. For example, for the "Barbara" image, at 0.50 bpp SLCCA outperforms EZW and SPIHT by 1.75 dB and 0.89 dB in PSNR, respectively. It is also observed that SLCCA works extremely well for images with large texture regions. For eight typical 256 256 grayscale texture images compressed at 0.40 bpp, SLCCA outperforms SPIHT by 0.32 dB{ 0.70 dB. This outstanding performance is achieved without any Optimal Bit Allocation procedure. Thus both the encoding and decoding procedures are fast
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significance linked connected component analysis for wavelet image coding
IEEE Transactions on Image Processing, 1999Co-Authors: Bingbing Chai, J Vass, Xinhua ZhuangAbstract:The success in wavelet image coding is mainly attributed to a recognition of the importance of data organization and representation. There have been several very competitive wavelet coders developed, namely, Shapiro's (1993) embedded zerotree wavelets (EZW), Servetto et al.'s (1995) morphological representation of wavelet data (MRWD), and Said and Pearlman's (see IEEE Trans. Circuits Syst. Video Technol., vol.6, p.245-50, 1996) set partitioning in hierarchical trees (SPIHT). We develop a novel wavelet image coder called significance-linked connected component analysis (SLCCA) of wavelet coefficients that extends MRWD by exploiting both within-subband clustering of significant coefficients and cross-subband dependency in significant fields. Extensive computer experiments on both natural and texture images show convincingly that the proposed SLCCA outperforms EZW, MRWD, and SPIHT. For example, for the Barbara image, at 0.25 b/pixel, SLCCA outperforms EZW, MRWD, and SPIHT by 1.41 dB, 0.32 dB, and 0.60 dB in PSNR, respectively. It is also observed that SLCCA works extremely well for images with a large portion of texture. For eight typical 256/spl times/256 grayscale texture images compressed at 0.40 b/pixel, SLCCA outperforms SPIHT by 0.16 dB-0.63 dB in PSNR. This performance is achieved without using any Optimal Bit Allocation procedure. Thus both the encoding and decoding procedures are fast.
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Significance-linked connected component analysis for wavelet image coding
1999Co-Authors: Bingbing Chai, J Vass, Xinhua ZhuangAbstract:Abstract- Recent success in wavelet image coding is mainly attributed to the recognition of importance of data organization and representation. There have beenseveral very competitive wavelet coders developed, namely, embedded zerotree wavelets (EZW), morphological representation of wavelet data (MRWD), and set partitioning in hierarchical trees (SPIHT). In this paper, we developanovel wavelet image coder called signi cance-linked connected component analysis (SLCCA) of wavelet coe cients that extends MRWD by exploiting both within-subband clustering of signi cant coe cients and cross-subband dependency in significant elds. Computer experiments on both natural and texture images show convincingly that the proposed SLCCA outperforms EZW, MRWD, and SPIHT as well. For example, for the \Barbara " image, at 0.50 bpp SLCCA outperforms EZW and SPIHT by 1.71 dB and 0.85 dB in PSNR, respectively. It is also observed that SLCCA works extremely well for images with a large portion of texture. This outstanding performance is achieved without using any Optimal Bit Allocation procedure. Thus both the encoding and decoding procedures are fast
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Significance-linked connected component analysis for wavelet image coding
1997Co-Authors: Bingbing Chai, J Vass, Xinhua ZhuangAbstract:Recent success in wavelet image coding is mainly attributed to recognition of the importance of data organization and representation. There have been several very competitive wavelet coders developed, namely, Shapiro's embedded zerotree wavelets (EZW), Servetto et al.'s morphological representation of wavelet data (MRWD), and Said and Pearlman's set partitioning in hierarchical trees (SPIHT). In this paper, we develop a novel wavelet image coder called significance-linked connected component analysis (SLCCA) of wavelet coefficients that extends MRWD by exploiting both within-subband clustering of significant coefficients and cross-subband dependency in significant fields. Extensive computer experiments on both natural and texture images show convincingly that the proposed SLCCA outperforms EZW, MRWD, and SPIHT. For example, for the \Barbara " image, at 0.5 bpp SLCCA outperforms EZW and SPIHT by 1.75 dB and 0.89 dB in PSNR, respectively. This outstanding performance is achieved without using any Optimal Bit Allocation procedure, thus both the encoding and decoding procedures are fast
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Significance-linked connected component analysis for wavelet image coding
1997Co-Authors: Bingbing Chai, J Vass, Xinhua ZhuangAbstract:Recent success in wavelet image coding is mainly attributed to recognition of the importance of data organization and representation. There have been several very competitive wavelet coders developed, namely, Shapiro's embedded zerotree wavelets (EZW), Servetto et al.'s morphological representation of wavelet data (MRWD), and Said and Pearlman's set partitioning in hierarchical trees (SPIHT). In this paper, we developanovel wavelet image coder called significance-linked connected component analysis (SLCCA) of wavelet coefficients that extends MRWD by exploiting both within-subband clustering of significant coefficients and cross-subband dependency in significant fields. Extensive computer experiments on both natural and texture images show convincingly that the proposed SLCCA outperforms EZW, MRWD, and SPIHT. For example, for the "Barbara" image, at 0.25 bpp SLCCA outperforms EZW, MRWD and SPIHT by 1.41 dB, 0.32 dB and 0.60 dB in PSNR, respectively. It is also observed that SLCCA works extremely well for images with a large portion of texture. For eight typical 256 256 grayscale texture images compressed at 0.40 bpp, SLCCA outperforms SPIHT by 0.16 dB-0.63 dB in PSNR. This outstanding performance is achieved without using any Optimal Bit Allocation procedure. Thus both the encoding and decoding procedures are fast
J W Modestino - One of the best experts on this subject based on the ideXlab platform.
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combined source channel coding schemes for video transmission over an additive white gaussian noise channel
IEEE Journal on Selected Areas in Communications, 2000Co-Authors: M Bystrom, J W ModestinoAbstract:There has been an increased interest in the transmission of digital video over real-world transmission media, such as the direct broadcast satellite (DBS) channel. Video transmitted over such a channel is subject to degradation due, in part, to additive white Gaussian noise (AWGN). Some form of forward error-control (FEC) coding may be applied in order to reduce the effect of the noise on the transmitted Bitstream; however, determination of the appropriate level of FEC coding is generally an unwieldy and computationally intensive problem, as it may depend upon a variety of parameters such as the type of video, the available bandwidth, and the channel SNR. More specifically, a combined source-channel coding approach is necessary in Optimally allocating rate between source and channel coding subject to a fixed constraint on overall transmission bandwidth. In this paper we develop a method of Optimal Bit Allocation under the assumption that the distortion is additive and independent on a frame-by-frame basis. A set of universal operational distortion-rate characteristics is developed which balances the tradeoff between source coding accuracy and channel error protection for a fixed overall transmission rate and provides the basis for the Optimal Bit Allocation approach. The results for specific source and channel coding schemes show marked improvement over suboptimum choices of channel error protection. In addition, we show that our results approach information-theoretic performance bounds which are developed in this work.
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combined source channel coding schemes for video transmission over an additive white gaussian noise channel
IEEE Journal on Selected Areas in Communications, 2000Co-Authors: M Bystrom, J W ModestinoAbstract:There has been an increased interest in the transmission of digital video over real-world transmission media, such as the direct broadcast satellite (DBS) channel. Video transmitted over such a channel is subject to degradation due, in part, to additive white Gaussian noise (AWGN). Some form of forward error-control (FEC) coding may be applied in order to reduce the effect of the noise on the transmitted Bitstream; however, determination of the appropriate level of FEC coding is generally an unwieldy and computationally intensive problem, as it may depend upon a variety of parameters such as the type of video, the available bandwidth, and the channel SNR. More specifically, a combined source-channel coding approach is necessary in Optimally allocating rate between source and channel coding subject to a fixed constraint on overall transmission bandwidth. In this paper we develop a method of Optimal Bit Allocation under the assumption that the distortion is additive and independent on a frame-by-frame basis. A set of universal operational distortion-rate characteristics is developed which balances the tradeoff between source coding accuracy and channel error protection for a fixed overall transmission rate and provides the basis for the Optimal Bit Allocation approach. The results for specific source and channel coding schemes show marked improvement over suboptimum choices of channel error protection. In addition, we show that our results approach information-theoretic performance bounds which are developed in this work.
Xiaoyan Sun - One of the best experts on this subject based on the ideXlab platform.
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Optimal Bit Allocation for ctu level rate control in hevc
IEEE Transactions on Circuits and Systems for Video Technology, 2017Co-Authors: Zulin Wang, Xiaoyan SunAbstract:For High Efficiency Video Coding (HEVC), the R– $\lambda $ scheme is the latest rate control (RC) scheme, which investigates the relationships among allocated Bits, the slope of rate-distortion (R-D) curve $\lambda $ , and quantization parameter. However, we argue that Bit Allocation in the existing R– $\lambda $ scheme is not Optimal. In this paper, we therefore propose an Optimal Bit Allocation (OBA) scheme for coding tree unit level RC in HEVC. Specifically, to achieve the OBA, we first develop an optimization formulation with a novel R-D estimation, instead of the existing R– $\lambda $ estimation. Unfortunately, it is intractable to obtain a closed-form solution to the optimization formulation. We thus propose a recursive Taylor expansion (RTE) method to iteratively solve the formulation. As a result, an approximate closed-form solution can be obtained, thus achieving OBA and Bit reAllocation. Both theoretical and numerical analyses show the fast convergence speed and little computational time of the proposed RTE method. Therefore, our OBA scheme can be achieved at little encoding complexity cost. Finally, the experimental results validate the effectiveness of our scheme in three aspects: R-D performance, RC accuracy, and robustness over dynamic scene changes.