一种MPEG压缩域的运动对象快速提取算法

针对目前压缩域直接得到的运动矢量过于稀疏且不可靠,导致运动对象分割精度不高等问题,提出一种适合于MPEG视频流的压缩域运动对象提取算法。它先对MPEG码流进行熵解码得到的运动矢量场进行可靠性度量校正、置密和滤波处理,并采用基于块的区域增长算法得到每个对象的大致运动区域;然后解码属于运动区域的块,并把被还原的每个位置的像素值分布视为高斯分布,用统计的方法建立其高斯模型,通过阈值判断可靠地提取出最终具有像素精度运动对象。仿真实验表明,该算法可以有效地去除运动矢量噪声的影响,分割精度显著提高,并且具有较高的处理速度。对于QCIF 格式的视频码流, 每秒可以处理约50帧。     

基于H．264压缩域的实时运动对象分割算法

在压缩域内直接分割运动对象对于有实时要求的应用而言是十分必要的，H．264以其优越的压缩效率已经在许多应用中逐渐取代了MPEG-2／4，但有关在H．264压缩域内进行运动对象分割的研究还很少。为此提出了一种从H.264压缩域实时分割运动对象的算法，该算法首先对从H．264视频中提取出的原始运动矢量场进行时域和空域的归一化，接着通过对连续多帧的运动矢量场进行累积来增强显著的运动信息；然后对累积运动矢量场进行全局运动补偿，同时利用快速的统计区域生长算法按照运动相似性将其分割成多个区域；最后利用运动矢量场的方向角直方图来判断出属于运动对象的分割区域，以组成运动对象。通过对多个MPEG-4测试序列的实验结果表明，该方法不仅能够从H．264压缩域中实时地分割出运动对象，且具有良好的分割质量。     

一种基于冗余小波变换的快速运动估计算法

由于冗余小波变换克服了离散小波变换的移变性,在冗余小波域进行运动估计可以达到很好的效果,其缺点是算法的时间复杂度过高。在分析视频序列的运动特性和已有的运动估计算法的基础上,提出一种快速的基于冗余小波变换的运动估计算法。在冗余小波域提取潜在运动区域并对图像块的运动剧烈程度进行划分,在此基础上对不同类型的图像块采取不同的搜索策略,从而减少了运动估计中不必要的搜索。实验结果表明,该方法较经典的基于冗余小波变换的运动估计算法在时间复杂度方面具有优势。     

基于H.264的运动对象快速分割算法

提出一种视频的压缩域与像素域特征结合的运动对象分割算法。该算法在压缩域对运动矢量场进行时空域滤波和累加处理,用空域差异度分割算法提取出运动对象区域,把提取得到的运动对象区域经一定的扩展映射到像素域,在像素域中使用基于高斯的马尔可夫随机场模型细分割运动对象。实验结果表明,该算法分割效率高,分割的运动对象完整性好、精度较高。     

面向视频会议的运动估计快速算法

针对H.264/AVC视频压缩算法中运动估计模块计算复杂度高的问题,提出了一种基于积分图像的运动估计快速算法.算法通过对单元块进行预计算求和,在块匹配运算时使用单元块级绝对差值.该算法能够在保证视频编码质量的前提下,大幅度提高运动估计模块的计算效率.算法适用于视频会议等要求视频实时压缩的应用.     

基于EM聚类的H.264压缩域视频对象实时分割算法

从压缩域直接分割视频对象比传统的像素域分割具有快速高效的特点,目前已有不少从MPEG域分割的方法,但从H.264压缩域分割的甚少。为此提出一种基于H.264域的实时分割运动对象方法,该算法先对当前视频帧进行全局运动估计和补偿,然后对4×4的运动矢量场进行分类处理,最后对非零运动矢量使用改进的EM聚类分割算法。本文算法对多个视频序列进行了实验,结果表明,该算法针对静止背景和运动背景的视频序列都能达到较精确的实时分割。     

基于低频子图的运动估计算法

为了减少运动估计的计算复杂度并提高其搜索性能,提出了一种基于低频子图的运动估计算法。该算法首先将当前帧和参考帧通过低通滤波器得到数据量减为1/4的低频子图,然后用全搜索得到最佳匹配的低频子块,最后对低频子块所覆盖的原参考帧区域进行精细搜索得到最优点。实验结果表明,与传统运动估计算法相比,该算法极大的提高了运动估计的精确度和降低了计算复杂度,并且对各类视频都有很高的鲁棒性。     

一种动态场景下基于时空信息的视频对象提取算法

在实际应用中,许多视频序列具有运动背景,使得从其中提取视频对象变得复杂,为此提出了一种基于运动估计和图形金字塔的动态场景下的视频对象提取算法。该算法首先引入了相位相关法求取运动向量,因避免了视频序列中光照变化的影响,故可提高效率和稳健性;接着再根据参数模型进行全局运动估计来得到最终运动模板;然后利用图形金字塔算法对当前模板内图像区域进行空间分割,最终提取出语义视频对象。与现有算法相比,对于从具有动态场景的视频流中提取运动对象的情况,由于使用该算法能有效地避开精准背景补偿,因而不仅节省了计算量,而且提取出来的语义对象精度较高。实验表明,无论是对动态场景中刚性还是非刚性运动物体的分割,该算法都具有较好的效果。     

一种基于H.264的可变块快速运动估计算法

H.264是最新的视频编码标准,它相对于以前的视频编码标准在编码效率上有了巨大的提高。高编码效率得益于采用了一系列新的编码技术,这也导致了较高的计算复杂度。H.264运用了可变块运动估计方法,这也是H.264编码过程中最耗时的模块。提出了一种基于H.264的可变块快速运动估计算法。该算法基于以下3种策略:静止块的预测、非静止块的预测搜索和合并过程中的自适应精细搜索。试验结果证明,该算法能够将计算复杂度降低到快速全搜索运动估计算法的3%,而PSNR和码率几乎与快速全搜索算法得到的结果相当。     

一种压缩域中的快速运动目标提取算法

论文提出了一种工作于MPEG压缩域的快速运动目标提取算法。算法以通过部分解码得到的运动向量和亮度分量的直流DCT系数作为输入,提取P帧的运动目标。首先采用鲁棒性回归分析估计全局运动,标记出与全局运动不一致的宏块,得到运动块的分布;然后将运动向量场插值作为时间域的特征,将重构的直流图像转换到LUV颜色空间作为空间域的特征,采用快速平均移聚类找到时间和空间特征具有相似性的区域,得到细化的区域边界;最后结合运动块分布和聚类分析的结果,通过基于马尔可夫随机场的统计标号方法进行背景分离,得到运动目标的掩模。实验结果表明该算法可以有效地消除运动向量噪声的影响,并有很高的处理速度,对于CIF格式的视频码流,每秒可以处理约50帧。     

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。