Model-Based Video Classification toward Hierarchical Representation,Indexing and Access

In this paper, we develop a content-based video classification approach to support semantic categorization, high-dimensional indexing and multi-level access. Our contributions are in four points: (a) We first present a hierarchical video database model that captures the structures and semantics of video contents in databases. One advantage of this hierarchical video database model is that it can provide a framework for automatic mapping from high-level concepts to low-level representative features. (b) We second propose a set of useful techniques for exploiting the basic units (e.g., shots or objects) to access the videos in database. (c) We third suggest a learning-based semantic classification technique to exploit the structures and semantics of video contents in database. (d) We further develop a cluster-based indexing structure to both speed-up query-by-example and organize databases for supporting more effective browsing. The applications of this proposed multi-level video database representation and indexing structures for MPEG-7 are also discussed.     

MPEG-4编码技术应用及FPGA实现

为满足视频通信、智能化监控等的需求，研究了MPEG-4编码技术的应用特点，设计了基于FPGA的MPEG-4编码器IP。通过分类比较的方法，研究分析了MPEG-4编码技术在不同类型中的应用方案，总结归纳了各类应用的特点，为进一步提高编码器的效率、满足低功耗的要求，在FPGA上设计并实现了MPEG-4编码器。经测试表明：该设计方案编码高效，符合实时视频通信的需求，可广泛应用在移动视频通信、远程无线监控等领域。     

MPEG-2视频解码器在DirectShow中的实现

MPEG-2是目前应用最为广泛的数字音视频编码国际标准,大部分数字音视频节目是以MPEG-2的形式存在.DirectShow是目前windows操作系统上的优秀的多媒体开发编程接口.提出一个MPEG-2视频解码器在DirectShow中的实现方案.这一实现在多媒体应用中具有广泛的参考价值.     

MPEG的新发展——多媒体框架标准MPEG-21

标准化是产业化活动成功的前提，视、音频编码的各种国际标准的制定集中地反映了视、音频编码技术发展的水平．目前，图象压缩方面的标准主要有MPEG系列(MPEG-1，MPEG-2，MPEG-4，MPEG-7和MPEG-21标准)，以及H．26X系列(H．261，H．263标准)和静止图象压缩标准JPEG．为了使人们对图象压缩标准有所了解，以进一步推动图象压缩方面的研究，首先对MPEG系列的各种已有标准及其应用进行了概述，然后着重讨论了MPEG中的新面孔——正在开发的MPEG-21标准，并就其目标、用户需求、技术要素、关键任务、应用领域以及工作计划做了较详细的描述．     

Performance analysis of cell discarding techniques for best effort video communications over ATM networks

With increasing interest in the transmission of audio–visual applications over ATM best effort services, efficient video-oriented control mechanisms for improving the video quality in the presence of loss have to be designed. In this paper, we propose and evaluate two new slice-based discard schemes for use with available bit rate and guaranteed frame rate services (e.g. formerly UBR+). The schemes adaptively and selectively adjust the discard level to switch buffer occupancy and video cell payload types. To improve their performance, we also introduce a dynamic frame-level priority data partition technique based on MPEG data structure and feedback from the network. To support these mechanisms, enhancements to the ATM adaptation layer 5 and a new MPEG-2 encapsulation strategy are also proposed. The presented quality of picture (QoP) control framework is evaluated using simulation and actual MPEG video data. The overall aim of the framework is double. First, ensuring a graceful picture quality degradation by minimizing cell loss probability for critical video data, and second optimizing the network effective throughput by reducing transmission of non useful data. In comparison to previous approaches, the performance evaluation have shown a significant reduction of the bad throughput and minimization of losses of intra- and predictive-coded frames at both cell and slice layers.     

MPEG-1/2到MPEG-4码流转换的研究与实现

该文研究并实现了MPEG-1/2码流到MPEG-4码流的转换,包括MPEG-1/2码流的解码及其优化,MPEG-4视音频码流的编码及其优化,及编码后生成的MPEG-4视音频码流的合成。     

Integrated Mining of Visual Features, Speech Features, and Frequent Patterns for Semantic Video Annotation

To support effective multimedia information retrieval, video annotation has become an important topic in video content analysis. Existing video annotation methods put the focus on either the analysis of low-level features or simple semantic concepts, and they cannot reduce the gap between low-level features and high-level concepts. In this paper, we propose an innovative method for semantic video annotation through integrated mining of visual features, speech features, and frequent semantic patterns existing in the video. The proposed method mainly consists of two main phases: 1) Construction of four kinds of predictive annotation models, namely speech-association, visual-association, visual-sequential, and statistical models from annotated videos. 2) Fusion of these models for annotating un-annotated videos automatically. The main advantage of the proposed method lies in that all visual features, speech features, and semantic patterns are considered simultaneously. Moreover, the utilization of high-level rules can effectively complement the insufficiency of statistics-based methods in dealing with complex and broad keyword identification in video annotation. Through empirical evaluation on NIST TRECVID video datasets, the proposed approach is shown to enhance the performance of annotation substantially in terms of precision, recall, and F-measure.     

On fast microscopic browsing of MPEG-compressed video

MPEG has been established as a compression standard for efficient storage and transmission of digital video. However, users are limited to VCR-like (and tedious) functionalities when viewing MPEG video. The usefulness of MPEG video is presently limited by the lack of tools available for fast browsing, manipulation and processing of MPEG video. In this paper, we first address the problem of rapid access to individual shots and frames in MPEG video. We build upon the compressed-video-processing framework proposed in [1, 8], and propose new and fast algorithms based on an adaptive mixture of approximation techniques for extracting spatially reduced image sequence of uniform quality from MPEG video across different frame types and also under different motion activities in the scenes. The algorithms execute faster than real time on a Pentium personal computer. We demonstrate how the reduced images facilitate fast and convenient shot- and frame-level video browsing and access, shot-level editing and annotation, without the need for frequent decompression of MPEG video. We further propose methods for reducing the auxiliary data size associated with the reduced images through exploitation of spatial and temporal redundancy. We also address how the reduced images lead to computationally efficient algorithms for video analysis based on intra- and inter-shot processing for video database and browsing applications. The algorithms, tools for browsing and techniques for video processing presented in this paper have been used by many in IBM Research on more than 30 h of MPEG-1 video for video browsing and analysis.     

多媒体数据压缩标准—MPEG系列

随着各种多媒体数据压缩标准的制定及计算机硬件、网络技术的发展，多媒体信息的应用呈现出爆炸式的增长。为了适应用户终端的多样性及网络自身的传输特性，20世纪90年代后期，一些国际标准化组织制定了几个多媒体数据压缩标准，并且获得了成功的应用，其中最主要的是MPEG系列。在此主要从视频的编码原理，视频数据组织结构和应用领域等方面对MPEG－1、MPEG－2、MPEG－4和MPEG－7做了一些介绍。     

基于MPEG-7的视频语义检索系统

设计和实现一个支持语义的分布式视频检索系统:"语寻"。该系统利用一个改进的视频语义处理工具(该工具基于IBM VideoAnnEx标注工具,并增加镜头语义图标注和自然语言处理的功能)对视频进行语义分析和标注,生成包含语义信息的MPEG-7描述文件,然后对视频的MPEG-7描述文件建立分布式索引,并同时分布式存储视频文件;系统提供丰富的Web查询接口,包括关键字语义扩展查询,语义图查询以及自然语句查询,当用户提交语义查询意图后,便能够迅速地检索到感兴趣的视频和片段,并且可以浏览点播;整个系统采用分布式架构,具备良好的可扩展性,并能够支持海量视频信息的索引和检索。     

图像压缩技术及其进展

本文重点对用于静止图像压缩的基于分形的方法和小波变换进行了分析和讨论．对用于活动图像压缩的ＭＰＥＧ系列进行了分析和介绍，并且对ＭＰＥＧ—４建议中基于模型的编码方法进行了介绍．     

Web-based delivery of medical multimedia contents using an MPEG-4 system

Moving picture expert group compression standard version 4 (MPEG-4) is a standard for video coding aimed at multimedia applications. MPEG-4 was developed to enable high compression rate in a low bitrate transmission via the Internet or mobile telecommunications. Although these characteristics of MPEG-4 are suitable for telemedicine, little is known about the possibility of using this technology in the field of telemedicine. We evaluated the quality of MPEG-4-encoded medical video streams and compared them with original analogue videos and audio-video-interleave (AVI) files. Although MPEG-4 video streams have the advantage of small file size, they were found to be inferior to original videos and AVI files in terms of smoothness of motion pictures, sharpness of images and clearness of sound. Illegibility of characters was a major problem in MPEG-4 files. The score for total impression of MPEG-4 files was significantly lower than those for AVI files. The results of this study suggest that the quality of MPEG-4-encoded video streams is not adequate for telemedicine.     

Video Semantic Event/Concept Detection Using a Subspace-Based Multimedia Data Mining Framework

In this paper, a subspace-based multimedia data mining framework is proposed for video semantic analysis, specifically video event/concept detection, by addressing two basic issues, i.e., semantic gap and rare event/concept detection. The proposed framework achieves full automation via multimodal content analysis and intelligent integration of distance-based and rule-based data mining techniques. The content analysis process facilitates the comprehensive video analysis by extracting low-level and middle-level features from audio/visual channels. The integrated data mining techniques effectively address these two basic issues by alleviating the class imbalance issue along the process and by reconstructing and refining the feature dimension automatically. The promising experimental performance on goal/corner event detection and sports/commercials/building concepts extraction from soccer videos and TRECVID news collections demonstrates the effectiveness of the proposed framework. Furthermore, its unique domain-free characteristic indicates the great potential of extending the proposed multimedia data mining framework to a wide range of different application domains.     

MPEG的发展与前瞻

MPEG专家委员会及其制定的标准是实现各类数字多媒体(包括视频,音频等)的准则,该文回顾了MPEG的发展历史,尤其详细分析了最新的MPEG-4和MPEG-7标准并对MPEG的未来做了大胆的预测。     

视频语义分析内容表征方式研究

从视觉和声音两方面对视频语义内容的表征技术进行研究。采用能反映时间语义约束、语义变化的帧切片策略选取关键帧，用时空注意力模型选择空域的内容，用分类器对这些区域进行基本语义分类识别，建立不同时间声音段的随机模型，进行声音语义内容表示和基本声音语义提取。实验表明，视频内容表征方式能简洁地表示视频的语义内容，有效提取视频基本语义。