基于 OpenH323的MPEG-4视频传输

H.323协议是当前发展非常成熟的基于IP网络的视频会议协议,MPEG-4是一种性能非常优越的视频压缩标准,研究MPEG-4内容在H.323协议上的传输有极其重要的意义.它在诸如视频会议、远程监控、交互式网络视频、多媒体电子邮件、视频新闻等方面有着广泛的应用.文中通过MPEG-4视频在OpenH323系统中传输的研究来实现在IP网络中基于H.323协议的MPEG-4视频传输.给出了MPEG-4 Simple Profile视频在OpenH323系统中传输的方案并与采用H.261/263视频编码标准时的结果进行了比较.     

基于OpenH323的MPEG-4视频传输

H.323协议是当前发展非常成熟的基于IP网络的视频会议协议,MPEG-4是一种性能非常优越的视频压缩标准,研究MPEG-4内容在H.323协议上的传输有极其重要的意义。它在诸如视频会议、远程监控、交互式网络视频、多媒体电子邮件、视频新闻等方面有着广泛的应用。文中通过MPEG-4视频在OpenH323系统中传输的研究来实现在IP网络中基于H.323协议的MPEG-4视频传输。给出了MPEG-4SimpleProfile视频在OpenH323系统中传输的方案并与采用H.261/263视频编码标准时的结果进行了比较。     

基于H.323协议的H.264视频传输

通过研究H.264标准在Openh323系统中的应用,实现了在IP网络中基于H.323协议的H.264视频传输,给出了H.264在Openh323系统中的传输方案,并与H.261和H.263编码标准的结果进行了比较分析,得到了令人满意的实验结果。     

H.263压缩协议在H.323会议系统中的嵌入

针对H.323多媒体会议系统中视频压缩采用H.261协议所带来的重建质量差、运动不连续、编码效率低等问题，提出了在H.323中嵌入高效的编码算法H.263协议来改善实时视频通信的质量，分析了在C 平台上H.263视频编解码在H.323中的嵌入过程，并取和最令人满意的实验结果。     

视频传输中的码率控制技术研究进展毕迎春王相海

码率控制技术对提高和平滑解码视频质量起着至关重要的作用。近年来各种视频编码标准和应用都对码率控制技术进行了大量的研究,如基于H.261和H.263的视频会议,基于MPEG-1和MPEG-2的媒体存储,以及最新的基于MPEG-4视频对象编码。首先对码率控制问题进行了基本描述,然后介绍了标准中的经典码率控制技术,接着将目前的码率控制技术归纳为3类:基于DCT视频编码器的码率控制技术、基于小波视频编码器的码率控制技术和精细粒度可分级视频编码的码率分配算法,并对这三类码率控制方法的发展进行了概括性阐述与比较性研究,讨论了各种算法的基本思想及其优缺点,最后对视频传输中的码率控制技术的未来发展趋势进行了展望。     

新一代视频编码国际标准的研究

视频压缩编码国际标准的制定，极大地促进了多媒体通信技术的发展。本文系统地研究了由国际标准化组织(ISO)和国际电信联盟(ITU)制定的视频压缩编码的H．261、MPEG-1、MPEG-2、H．263、MPEG-4、MPEG-7、H．26L等国际标准，分析了这些国际标准的特点和性能，说明了它们的应用领域和发展现状。对其中最新的视频编码标准H.26L进行了重点介绍，详细分析了H．26L中用到的各种新的技术和算法。     

H.263解码器在TMS320C80上的实现

文章介绍了基于TMS320C80的H.263解码系统实现。结合C80的特点,对H.263视频编解码标准中开放部分的算法进行了改进。对CIF格式图像解码,可达到12.5帧/秒的帧率。进而证明可用H.263取代H.261进行低码率视频解码。     

理性区分开放式和单厂商IP监控系统

许多业内人士认为，开放式或多厂商IP视频系统采用开放性的行业标准，以实现交互操作。这种说法其实并不成立。IP视频牵涉到多个方面，基于多个标准。其中之一是视频压缩标准，MPEG-2，MPEG-4，H.263、H.264和JPEG-2000都是获得认可的视频压缩标准，并在IP CCTV行业内普遍应用。     

图像和视频编码技术的发展

本文展望图像和视频编码的趋势和未来,概括过去40年和当前最先进的图像和视频编码技术,在JPEG,JPEG2000,MPEG-1/2/4,H.261/3/4标准中对这些编码算法进行讨论。介绍了H.264标准在视频通信中针对差错恢复能力和网络适应性等方面应用的关键技术。     

国际主流视频编码标准优化代码的对比测试

以 H. 263、MPEG-4、H. 264三种标准作为测试对象 ,在 Win / Intel平台上测试了优化后编码器的计算效率、编码效率和码率控制精度 ,并对测试结果进行了比较和分析。测试数据为开发人员在一定硬件性价比的约束条件下实现视频编码器提供了参考。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

基于QTE的蒙古文显示机制研究与实现

蒙古语言是中国蒙古族使用的通用语言,由于蒙古文区别于其他文字的书写方式和其自身变形机制等特点,在很多通用的文字处理引擎中都不被支持。在嵌入式产品开发与应用领域中Linux加QTE已经成为流行方式。该文给出了一种在QTE环境上实现基于标准Unicode的蒙古文点阵显示和变形算法, 并自定义了支持蒙古文的QTE组件,扩展了QTE功能,为在Linux加QTE方式的嵌入式体系结构中处理蒙古文提供了一种解决方法。