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Fast scalable coding based on a 3D Low Bit Rate Fractal Video Encoder 12

Fast Scalable Coding based on a 3D Low Bit Rate Fractal Vide...

12th International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications (VISIGRAPP)

作者： de Lima, Vitor Moreira, Thierry Pedrini, Helio Schwartz, William Robson Univ Estadual Campinas Inst Comp BR-13083852 Campinas SP Brazil Univ Fed Minas Gerais Dept Comp Sci BR-31270010 Belo Horizonte MG Brazil

ISBN: (纸本)9789897582257

Video transmissions usually occur at a fixed or at a small number of predefined bit rates. This can lead to several problems in communication channels whose bandwidth can vary along time (e.g. wireless devices). This work proposes a video encoding method for solving such problems through a fine rate control that can be dynamically adjusted with low overhead. The encoder uses fractal compression and a simple rate distortion heuristic to preprocess the content in order to speed up the process of switching between different bit rates. Experimental results show that the proposed approach can accurately transcode a preprocessed video sequence into a large range of bit rates with a small computational overhead.

关键词： Video Compression Fractal Encoding Adaptive Transcoding scalable coding

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JOINT ENTROPY-scalable coding OF AUDIO SIGNALS

JOINT ENTROPY-SCALABLE CODING OF AUDIO SIGNALS

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IEEE International Conference on Acoustics, Speech and Signal Processing

作者： Movassagh, Mahmood Thiemann, Joachim Kabal, Peter McGill Univ Dept Elect & Comp Engn Montreal PQ Canada

ISBN: (纸本)9781467300469

A fine grain scalable coding for audio signals is proposed where the entropy coding of the quantizer outputs is made scalable. By constructing a Huffman-like coding tree where internal nodes can be mapped to reconstruction points, we can prune the tree to control the distortion of the quantizer. Our results show the proposed method improves existing similar work and significantly outperforms scalable coding based on reconstruction error quantization as used in practical systems, eg. MPEG-4 audio.

关键词： scalable coding Entropy coding Quantization

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Intra-frame dyadic spatial scalable coding based on a subband/wavelet framework for MPEG-4 AVC/H.264 scalable video coding

Intra-frame dyadic spatial scalable coding based on a subban...

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IEEE International Conference on Image Processing (ICIP 2007)

作者： Hsiang, Shih-Ta Motorola Labs ARC Multimedia Res Lab Schaumburg IL 60173 USA

ISBN: (纸本)9781424414369

This paper develops a new intra-frame dyadic spatial scalable coding framework based on a subband/wavelet coding approach for MPEG-4 AVC/H.264 scalable video coding (SVC). It is the first attempt in the literature to join the subband filter banks with the traditional macroblock and DCT based video coding system. We demonstrate that the current H.264 coding tools and syntax set can efficiently work together with the traditional subband filter banks for providing the improved efficiency for intra-frame dyadic spatial scalable coding. More importantly, unlike the classical wavelet coding, the proposed framework still allows the down-sampling filter to be flexibly designed to generate the ideal low resolution video for target applications. The proposed wavelet tool has been adopted by the JSVM for the next-phase SVC standard.

关键词： AVC H.264 scalable coding wavelet

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Optimization of Optical Flow for scalable coding 31

Optimization of Optical Flow for Scalable Coding

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Picture coding Symposium (PCS)

作者： Mathew, Reji Young, Sean I. Taubman, David Univ New South Wales Interact Visual Media Proc Lab Sydney NSW Australia

ISBN: (纸本)9781479977833

Optical flow or dense motion field representations provide an alternative to block based schemes and are capable of describing smooth motion flows without introducing any artificial block boundaries. However dense motion fields have not been widely adopted for video coding applications principally due to the prohibitive cost of communicating such detailed motion representations. In this paper our focus is on estimating dense motion fields subject to R-D constraints derived from wavelet based coding of the motion data. We develop a probabilistic framework for estimating dense motion fields that is capable of evaluating the trade-off between sparsity in the transformed domain and motion compensated distortion. R-D results show that we are able to improve upon traditional optical flow descriptions.

关键词： scalable coding motion estimation optical flow

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ON scalable coding OF HIDDEN MARKOV SOURCES 41

ON SCALABLE CODING OF HIDDEN MARKOV SOURCES

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41st IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)

作者： Salehifar, Mehdi Nanjundaswamy, Tejaswi Rose, Kenneth Univ Calif Santa Barbara Dept Elect & Comp Engn Santa Barbara CA 93106 USA

ISBN: (纸本)9781479999880

While several real world signals, such as speech, image and sensor network data, are modeled as hidden Markov sources (HMS) for recognition and analysis applications, their typical compression exploits temporal correlations by modeling them as simple (non-hidden) Markov sources. However, the inherent hidden Markov nature of these sources implies that an observed sample depends, in fact, on all past observations, thus rendering simple Markov modeling suboptimal. Motivated by this realization, previous work from our lab derived a technique to optimally quantize and compress HMS. In this paper we build on, and considerably extend, these results to the problem of scalable coding of HMS. At the base layer, as proposed earlier, the approach tracks an estimate of the state probability distribution and adapts the encoder structure accordingly. At the enhancement layer, the state probability distribution is refined using available information from past enhancement layer reconstructed samples, and this refined estimate is further combined with quantization information from the base layer, to effectively characterize the probability density of the current sample conditioned on all available information. We update code parameters on the fly, at each observation, at both the encoder and the decoder and at both layers. Experimental results validate the superiority of the proposed approach with considerable gains over standard predictive coding employing a simple Markov model.

关键词： scalable coding Hidden Markov Sources

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Robust video transmission over lossy packet networks using block-based fine granularity scalable coding

Robust video transmission over lossy packet networks using b...

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Conference on Visual Communications and Image Processing 2003

作者： He, YW Yang, SQ Tsinghua Univ Dept Comp Sci & Technol Beijing 100084 Peoples R China

ISBN: (纸本)0819450235

This paper proposes a robust video transmission system over lossy packet-switched networks with block-based fine granularity scalable (B-FGS) coding including source coding, efficient rate allocation and packetization, which works effectively when packet loss occurs. The compressed B-FGS bit-stream can be truncated in fine grain for its block-based bit-plane coding at enhancement layer. Therefore channel adaptive rate allocation can be implemented and the time-varying bandwidth can be exploited efficiently. Distortion associated rate allocation method is proposed to substitute Rate-Distortion optimal rate allocation in order to reduce the streaming server's complexity. In addition, packetizing with independent data provides robust video transmission, which restrains the error propagation across packets. Furthermore, in order to mitigate quality flicking of decoded video induced by packets loss, spatial interleaving is applied in packetizing. Thus, in proposed video transmission system, available bandwidth variation and packet loss, two key problems in video streaming applications, are well dealt with. In order to validate the effectiveness of proposed transmission system, MPEG-4 FGS transmission system and that with conditional retransmission are compared in simulations. Proposed transmission system is more robust to packet-loss errors than the other two, especially when packet-loss rate is high.

关键词： video transmission video streaming rate allocation packet loss scalable coding

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A novel multiple description scalable coding scheme for mobile wireless video transmission

A novel multiple description scalable coding scheme for mobi...

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Conference on Multimedia on Mobile Devices

作者： Zheng, HF Yu, L Chen, CW Fuzhou Univ Coll Informat Technol Fujian 350002 Peoples R China

ISBN: (纸本)0819456578

We proposed in this paper a novel multiple description scalable coding (MDSC) scheme based on in-band motion compensation temporal filtering (IBMCTF) technique in order to achieve high video coding performance and robust video transmission. The input video sequence is first split into equal-sized groups of frames (GOFs). Within a GOF, each frame is hierarchically decomposed by discrete wavelet transform. Since there is a direct relationship between wavelet coefficients and what they represent in the image content after wavelet decomposition, we are able to reorganize the spatial orientation trees to generate multiple bit-streams and employed SPIHT algorithm to achieve high coding efficiency. We have shown that multiple bit-stream transmission is very effective in combating error propagation in both Internet video streaming and mobile wireless video. Furthermore, we adopt the IBMCTF scheme to remove the redundancy for inter-frames along the temporal direction using motion compensated temporal filtering, thus high coding performance and flexible scalability can be provided in this scheme. In order to make compressed video resilient to channel error and to guarantee robust video transmission over mobile wireless channels, we add redundancy to each bit-stream and apply error concealment strategy for lost motion vectors. Unlike traditional multiple description schemes, the integration of these techniques enable us to generate more than two bit-streams that may be more appropriate for multiple antenna transmission of compressed video. Simulate results on standard video sequences have shown that the proposed scheme provides flexible tradeoff between coding efficiency and error resilience.

关键词： multiple description coding scalable coding motion-compensated temporal filtering error resilience error concealment mobile wireless channel

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scalable coding of Depth Images with Synthesis-Guided Edge Detection

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KSII TRANSACTIONS ON INTERNET AND INFORMATION SYSTEMS 2015年第10期9卷 4108-4125页

作者： Zhao, Lijun Wang, Anhong Zeng, Bing Jin, Jian Taiyuan Univ Sci & Technol Inst Digital Media & Commun Taiyuan 030024 Peoples R China Univ Elect Sci & Technol China Inst Image Proc Chengdu 611731 Peoples R China Hong Kong Univ Elect Sci & Technol Dept Elect & Comp Engn Kowloon Hong Kong Peoples R China

This paper presents a scalable coding method for depth images by considering the quality of synthesized images in virtual views. First, we design a new edge detection algorithm that is based on calculating the depth difference between two neighboring pixels within the depth map. By choosing different thresholds, this algorithm generates a scalable bit stream that puts larger depth differences in front, followed by smaller depth differences. A scalable scheme is also designed for coding depth pixels through a layered sampling structure. At the receiver side, the full-resolution depth image is reconstructed from the received bits by solving a partial-differential-equation (PDE). Experimental results show that the proposed method improves the rate-distortion performance of synthesized images at virtual views and achieves better visual quality.

关键词： depth image scalable coding inter-layer prediction depth difference synthesis-guided edge detection partial differential equation

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Asymptotically optimal scalable coding for minimum weighted mean square error

Asymptotically optimal scalable coding for minimum weighted ...

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Data Compression Conference (DCC 2001)

作者： Aggarwal, A Regunathan, SL Rose, K Univ Calif Santa Barbara Dept Elect & Comp Engn Santa Barbara CA 93106 USA

ISBN: (纸本)0769510310

In this paper, we derive an asymptotically optimal multi-layer coding scheme for entropy-coded scalar quantizers (SQ) that minimizes the weighted mean-squared error (WMSE). The optimal entropy-coded SQ is non-uniform in the case of WMSE. The conventional multi-layer coder quantizes the base-layer reconstruction error at the enhancement-layer, and is sub-optimal for the WMSE criterion. We consider the compander representation of the quantizer, and propose to implement scalability in the compressed domain. We show that such a multi-layer coding system achieves the operational rate-distortion bound given by the nun-scalable entropy-coded SQ, at the limit of high resolution. Simulation results for a synthetic memoryless Laplace source with mu -law companding are presented for various values of layer rates. Substantial gains are also achieved on the "real-world" sources of audio signals, when the optimal multi-layer approach is applied to a two-layer scalable MPEG-4 Advanced Audio Coder.

关键词： Mean square error Entropy coding quantizer Optimal audio signals minimum Scalability scalable coding quadratic errors Weighted Average asymptotic audio coder INHOMOGENITIES

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Region-based scalable coding for interactive image/video communications over networks

Region-based scalable coding for interactive image/video com...

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Conference on Hybrid Image and Signal Processing VIII

作者： Lee, JH Lee, G Yoon, S N Carolina State Univ Raleigh NC 27695 USA

ISBN: (纸本)0819444855

In this paper, we present a region-based scalable coding technique that can be used in interactive image/video communications. This method has a capability of near lossless coding for a specific region of interest (ROI), while the rest of the region is coded with high quality lossy codec. There are many potential applications of the region-based scalable video coding method in the areas of interactive communications such as storm tracking, wild fire and air traffic monitoring using satellite still images and near real time video sequences. It enables the server/client system to reduce data traffic across the networks while the quality of a specific area of interest chosen for each client's needs is still satisfied. We tested this technique by applying it to still images and traffic monitoring image sequences. The results consistently show high level of performance.

关键词： scalable coding region of interest wavelets

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