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Improving SPIHT using virtual encapsulation

CIRCUITS SYSTEMS AND SIGNAL PROCESSING 2004年第6期23卷 507-516页

作者： Kassim, AA SeeToh, CW Natl Univ Singapore Dept Elect & Comp Engn Singapore 119260 Singapore

In this paper, we propose a procedure that enhances the very low bit-rate coding performance of Set Partitioning in Hierarchical Trees (SPIHT)-based image coders. In SPIHT-based algorithms, all nodes with descendants in the LL band are initially added to the list of insignificant sets as type-A entries. Our experiments indicate that type-A nodes are highly likely to be insignificant during the sorting passes of the high bit planes. Our new procedure exploits this characteristic so that all these type-A nodes can be encapsulated into a single virtual node.

关键词： SPIET CSPIHT scalable coding virtual encapsulation

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Priors Guided Extreme Underwater Image Compression for Machine Vision and Human Vision

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IEEE JOURNAL OF OCEANIC ENGINEERING 2023年第3期48卷 888-902页

作者： Fang, Zhengkai Shen, Liquan Li, Mengyao Wang, Zhengyong Jin, Yanliang Shanghai Univ Sch Commun & Informat Engn Shanghai 200444 Peoples R China Shanghai Univ Key Lab Specialty Fiber Opt & Opt Access Networks Joint Int Res Lab Specialty Fiber Opt & Adv Commun Shanghai 200444 Peoples R China

A low bit-rate compression is required for underwater images due to the limited bandwidth in underwater acoustic communication, which limits performances of both machine analysis and human perception in most underwater applications. Few existing compression methods consider the unique characteristics of underwater images such as color shift and haze effect to better fulfill requirements of various applications under low bit-rates. To address this problem, we propose a novel extreme underwater image compression framework, which can provide scalability to support machine vision and human vision with the assistance of underwater priors. Specifically, the base layer is composed of a feature extractor and a generator, where global structural edges and high-level features of regions with a significant impact on machine analysis are extracted and used for reconstructing a feature-matching image for analysis purpose. Considering the negative influence of underwater imaging processes on machine vision, in this article, a feature degradation removal module guided by underwater priors is proposed to alleviate feature-level degradation via taking analysis-friendly enhanced images as auxiliary information. As for the enhancement layer aiming for human vision, the residual between the original image and the reconstruction from base layer is compressed. A feature attention block and a background light recovery block are designed utilizing features extracted from enhanced images and the underwater before further recovering the original scene with a good perception quality under low bit-rates. Experimental results demonstrate the superiority of our framework in both machine vision tasks and perception quality compared with traditional compression methods and learned-based methods.

关键词： Feature enhance generative compression scalable coding underwater image compression

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A scalable wideband speech codec using the wavelet packet transform based on the internet low bitrate codec

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COMPUTER SPEECH AND LANGUAGE 2019年 54卷 61-70页

作者： Seto, Koji Ogunfunmi, Tokunbo Santa Clara Univ Dept Elect Engn Santa Clara CA 95053 USA

Most recent speech codecs employ code excited linear prediction (CELP) and transmit side information to improve speech quality under packet loss. Another approach to achieve high robustness to packet loss is to use the frame independent coding scheme based on the internet low bitrate codec (iLBC). The scalable wideband speech codec based on the iLBC was previously presented and outperformed G.729.1 at most bit rates according to the objective quality. This paper presents improvements to the previous work. Specifically, we employ the wavelet packet transform (WPT) instead of the modified discrete cosine transform (MDCT) to enhance the quality, and evaluate the proposed codec based on both the objective and subjective quality measures. The objective quality evaluation results show that clear improvement is achieved and that the proposed codec outperforms G.729.1 at the bit rate of 18 kbps or higher under clean channel conditions and has higher robustness to packet loss than G.729.1. The informal subjective test results also show similar trends. (C) 2018 Elsevier Ltd. All rights reserved.

关键词： Wavelet packet transform (WPT) Internet low bitrate codec (iLBC) Packet loss scalable coding Speech coding Voice over Internet protocol (VoIP)

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Enhancement Layer coding for Chroma Sub-Sampled Screen Content Video

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 2022年第2期32卷 788-801页

作者： Heindel, Andreas Prestele, Benjamin Gehlert, Alexander Kaup, Andre Friedrich Alexander Univ Erlangen Nurnberg FAU Inst Multimedia Commun & Signal Proc D-91058 Erlangen Germany LogMeIn Inc D-01067 Dresden Germany

Prevalent video codec implementations deployed in the field often solely support chrominance sub-sampled video data represented by the YCbCr 4:2:0 format. For certain applications like screen sharing, however, chroma sub-sampling leads to disturbing artifacts, especially for text or graphics with thin lines. It is desirable to reduce these artifacts while maintaining compatibility with all user devices. For this reason, an enhancement layer coding framework for chroma-format scalable coding with specific focus on screen content is proposed in this paper. Based on an analysis of screen content data characteristics, the enhancement layer codec is optimized specifically for this content class, is of low algorithmic complexity, and applicable with any image or video codec for base layer compression in a joint coding system. The system is intentionally not designed as a general purpose lossless YCbCr 4:4:4 coding scheme, but instead chooses to close a quality gap that prevalent video codecs do not address. Experimental analysis reveals an average BD-PSNR gain in the RGB domain of 1.0 dB comparing the proposed two-layer scalable coding approach to single layer compression using base layer coding only. In relation to simulcast coding, an average BDR RGB difference of 8.1% is observed.

关键词： Encoding Decoding Standards Video codecs Image coding Hardware Receivers Video coding chroma sub-sampling scalable coding enhancement layer HEVC

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Authentication Schemes for Multimedia Streams: Quantitative Analysis and Comparison

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ACM TRANSACTIONS ON MULTIMEDIA COMPUTING COMMUNICATIONS AND APPLICATIONS 2010年第1期6卷 1–24页

作者： Hefeeda, Mohamed Mokhtarian, Kianoosh Simon Fraser Univ Sch Comp Sci Burnaby BC V5A 1S6 Canada

With the rapid increase in the demand for multimedia services, securing the delivery of multimedia content has become an important issue. Accordingly, the problem of multimedia stream authentication has received considerable attention by previous research and various solutions have been proposed. However, these solutions have not been rigorously analyzed and contrasted to each other, and thus their relative suitability for different streaming environments is not clear. This article presents comprehensive analysis and comparison among different schemes proposed in the literature to authenticate multimedia streams. Authentication schemes for nonscalable and scalable multimedia streams are analyzed. To conduct this analysis, we define five important performance metrics, which are computation cost, communication overhead, receiver buffer size, delay, and tolerance to packet losses. We derive analytic formulas for these metrics for all considered authentication schemes to numerically analyze their performance. In addition, we implement all schemes in a simulator to study and compare their performance in different environments. The parameters for the simulator are carefully chosen to mimic realistic settings. We draw several conclusions on the advantages and disadvantages of each scheme. We extend our analysis to authentication techniques for scalable streams. We pay careful attention to the flexibility of scalable streams and analyze its impacts on the authentication schemes. Our analysis and comparison reveal the merits and shortcomings of each scheme, provide guidelines on choosing the most appropriate scheme for a given multimedia streaming application, and could stimulate designing new authentication schemes or improving existing ones. For example, our detailed analysis has led us to design a new authentication scheme that combines the best features of two previous schemes.

关键词： Performance Multimedia authentication authentication schemes scalable coding multimedia security secure streaming multimedia streaming

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Evaluation of Asymmetric Stereo Video coding and Rate Scaling for Adaptive 3D Video Streaming

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IEEE TRANSACTIONS ON BROADCASTING 2011年第2期57卷 593-601页

作者： Saygili, Gorkem Gurler, Cihat Goktug Tekalp, A. Murat Koc Univ Coll Engn Istanbul Turkey

It is well known that the human visual system can perceive high frequencies in 3D stereo video, even if that information is present in only one of the views. Therefore, the best perceived 3D stereo video quality may be achieved by asymmetric coding where the reference and auxiliary (right and left) views are coded at unequal PSNR. However, the questions of what is the best level of asymmetry in order to maximize the perceived quality and whether asymmetry should be achieved by spatial resolution reduction or PSNR (quality) reduction have been open issues. We conducted extensive subjective tests, which indicate that if the reference view is encoded at sufficiently high quality and the auxiliary view is encoded at a lower quality but above a certain PSNR threshold, then the degradation in 3D video quality is unnoticeable. Since asymmetric coding by PSNR reduction gives finer control over achievable PSNR values over spatial resolution reduction, asymmetry by PSNR reduction allows us to encode at a point more close to this just-noticeable asymmetry PSNR threshold;hence will be preferred over the spatial resolution reduction method. Subjective tests also indicate that below this just-noticeable asymmetry threshold, where subtle artifacts start to appear, symmetric coding performs better than asymmetric coding in terms of perceived 3D video quality. Therefore, we show that the choice between asymmetric vs. symmetric coding depends on PSNR;hence, the available total bitrate. This paper also proposes a novel asymmetric scalable stereo video coding framework to enable adaptive stereoscopic video streaming taking full advantage of these observations and subjective test results.

关键词： Adaptive streaming scalable coding stereo rate adaptation stereo video 3D video quality evaluation

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Progressive coding of 3-D objects based on overcomplete decompositions

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 2006年第11期16卷 1338-1349页

作者： Tosic, Ivana Frossard, Pascal Vandergheynst, Pierre Ecole Polytech Fed Lausanne Signal Proc Inst CH-1015 Lausanne Switzerland

This paper presents a progressive coding scheme for 3-D objects, based on overcomplete signal expansions on the 2-D sphere. Due to increased freedom in the basis construction, redundant expansions have shown interesting approximation properties in the decomposition of signals with multidimensional singularities organized along embedded submanifolds. We propose to map simple 3-D models on 2-D spheres and then to decompose the signal over a redundant dictionary of oriented and anisotropic atoms living on the sphere. The signal expansion is computed iteratively with a matching pursuit algorithm, which greedily selects the most prominent components of the 3-D model. The decomposition therefore inherently represents a progressive stream of atoms, which is advantageously used in the design of scalable representations. An encoder is proposed that compresses the stream of atoms by adaptive coefficient quantization and entropy coding of atom indexes. Experimental results show that the novel coding strategy outperforms state-of-the-art progressive coders in terms of distortion, mostly at low bit rates. Furthermore, since the dictionary is built on structured atoms, the proposed representation simultaneously offers an increased flexibility for easy stream manipulations. We finally illustrate that advantage in the design of a view-dependent transmission scheme.

关键词： matching pursuit progressive coding scalable coding sparse approximations 3-D model compression 3-D representation and coding

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End-to-end security in the presence of intelligent data adapting proxies: The case of authenticating transcoded streaming media

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IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS 2005年第2期23卷 464-473页

作者： Gentry, C Hevia, A Jain, R Kawahara, T Ramzan, Z DoCoMo Commun Labs San Jose CA 95110 USA Univ Calif San Diego Dept Comp Sci & Engn La Jolla CA 92093 USA

We consider the problem of maintaining end-to-end security in the presence of intelligent proxies that may adaptively modify data being transmitted across a network. The video coding community considers this problem in the context of transcoding media streams, but their approaches either fail to address authentication or fail to provide meaningful security guarantees. We present two provably-secure schemes, LISSA and TRESSA,that allow an intelligent network intermediary to intercept a stream signed by a content provider, and adapt it dynamically, while preserving the ultimate receiver's ability to securely verify the content provider's signature (and, hence, authenticity and integrity of the data received). Our schemes allow the intermediary to selectively remove portions of the stream and, thus, permit common media transcoding techniques such as scalable compression and multiple file switching. Moreover, a content provider only has to encode and sign its entire data stream once, as opposed to nondynamically encoding and signing different versions for each anticipated combination of device, network configuration, and channel condition. Our implementation results demonstrate efficiency.

关键词： adaptive security digital signatures multiple file switching scalable coding

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Towards Analysis-Friendly Face Representation With scalable Feature and Texture Compression

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IEEE TRANSACTIONS ON MULTIMEDIA 2022年 24卷 3169-3181页

作者： Wang, Shurun Wang, Shiqi Yang, Wenhan Zhang, Xinfeng Wang, Shanshe Ma, Siwei Gao, Wen City Univ Hong Kong Dept Comp Sci Kowloon Hong Kong Peoples R China Univ Chinese Acad Sci Sch Comp Sci & Technol Beijing 100190 Peoples R China Peking Univ Inst Digital Media Beijing 100871 Peoples R China

Compactly representing visual information plays a fundamental role in optimizing the ultimate utility of myriad visual data-centered applications. Numerous approaches have been proposed to efficiently compress the texture and visual features for human visual perception and machine intelligence, respectively;however, much less work has been dedicated to studying the interactions between them. Here, we investigate the integration of feature and texture compression and show that a universal and collaborative visual information representation can be achieved in a hierarchical way. In particular, we study feature and texture compression in a scalable coding framework, where the base layer serves as the deep learning feature and the enhancement layer targets to perfectly reconstruct the texture. Based on the strong generative capability of deep neural networks, the gap between the base feature layer and enhancement layer is further filled with feature-level texture reconstruction, with the goal of further constructing texture representations from features. As such, the residuals between the original and reconstructed texture could be further conveyed in the enhancement layer. To improve the efficiency of the proposed framework, the base layer neural network is trained in a multitask manner such that the learned features enjoy both high-quality reconstruction and high-accuracy analysis. The framework and optimization strategies are further applied in face image compression, and promising coding performance has been achieved in terms of both rate-fidelity and rate-accuracy evaluations.

关键词： Image coding Visualization Standards Transform coding Feature extraction Image reconstruction Deep learning Feature compression texture compression scalable coding multitask learning

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Rate-Distortion-Memory Trade-Offs in Heterogeneous Caching Networks

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2020年第5期19卷 3019-3033页

作者： Hassanzadeh, Parisa Tulino, Antonia M. Llorca, Jaime Erkip, Elza NYU ECE Dept Tandon Sch Engn Brooklyn NY 11201 USA JP Morgan AI Res New York NY 10017 USA Univ Naples Federico II DIETI I-80125 Naples Italy Nokia Bell Labs Holmdel NJ 07733 USA

Caching at the wireless edge can be used to keep up with the increasing demand for high-definition wireless video streaming. By prefetching popular content into memory at wireless access points or end-user devices, requests can be served locally, relieving strain on expensive backhaul. In addition, using network coding allows the simultaneous serving of distinct cache misses via common coded multicast transmissions, resulting in significantly larger load reductions compared to those achieved with traditional delivery schemes. Most prior works simply treat video content as fixed-size files that users would like to fully download. This work is motivated by the fact that video can be coded in a scalable fashion and that the decoded video quality depends on the number of layers a user receives in sequence. Using a Gaussian source model, caching and coded delivery methods are designed to minimize the squared error distortion at end-user devices in a rate-limited caching network. The framework is very general and accounts for heterogeneous cache sizes, video popularities and user-file play-back qualities. As part of the solution, a new decentralized scheme for lossy cache-aided delivery subject to preset user distortion targets is proposed, which further generalizes prior literature to a setting with file heterogeneity.

关键词： Caching networks coded multicast scalable coding successive refinement lossy source coding

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