基于二进制特征描述器的图像匹配算法

图像特征点匹配在视觉系统中有广泛的应用。针对加速分割测试特征FAST和二进制稳健基元独立特征BRIEF算法中存在的问题进行改进。首先,在FAST算法中使用简化模板提取图像特征点,通过构建图像金字塔实现尺度不变性。接着,根据人类视觉系统原理改进BRIEF算法的点对采样模式,并通过特征点方向的计算实现图像的旋转不变性。最后,使用易于计算的海明距离度量各特征点的相似度实现特征匹配。实验表明,提出的图像匹配算法性能优于其他算法,而且运行速度更快。     

改进人工鱼群的ORB特征匹配算法

针对室内轮椅定位与地图构建中传统ORB（oriented FAST and rotated BRIEF）受到特征点检测与选取策略的影响导致特征匹配正确率不理想,提出一种改进人工鱼群的ORB特征匹配算法。使用改进后的FAST检测特征点,利用改进后的人工鱼群在组合优化问题中具有收敛速度快且易获得最优解的特点,在图像中计算出不同特征区域,根据特征点所在区域位置赋予其相应的状态,对不同状态的特征点选择保留或去除,使用汉明距离的RANSAC算法在特征区域之间进行特征匹配。实验结果表明,改进后的FAST在图像边缘处提取到更多的图像特征,在实际环境中改进后的ORB匹配算法平均正确匹配率达到了92.7%,比传统ORB平均正确匹配率高52.3%。     

基于距离融合的图像特征点匹配方法

针对ORB算法中特征点缺乏尺度不变性导致算法误匹配率高,以及二进制鲁棒独立基本特征（BRIEF）算法的描述子易受噪声影响的问题,提出了改进的特征点匹配方法。采用加速的具有鲁棒性的特征（SURF）算法进行特征点提取,利用带有方向信息的BRIEF算法进行特征点描述;在特征点邻域内选取随机点对,并对随机点对的灰度大小比较和相似度比较分别进行编码,采用汉明距离计算两种编码的差异;利用自适应加权融合的方式实现特征点相似性距离度量。实验结果表明,改进方法对于尺度变化、光照变化以及模糊变化的图像具有更好的适应性,与传统ORB特征点匹配方法相比能够获得更高的特征点正确匹配率,且该特征点匹配方法可用于改善图像拼接的性能。     

基于特征点匹配的步态识别

基于图像特征点匹配的算法思想,结合步态能量图(GEI),提出了一种适用于2幅GEI匹配的步态识别方法.在GEI中采用改进的FAST算法提取特征点,并采用具有良好特征描述性能的BRIEF算法描述特征点.考虑到GEI匹配不要求特征点具有旋转不变性,提出了一种质心角约束条件加速特征点的匹配.在CASIA数据库B库上的实验结果表明:方法在识别率和特征计算时间上均具有良好的表现.     

尺度及主方向改正的ORB特征匹配算法

针对二进制描述算法（Oriented fast and Rotated Brief，ORB）尺度性配准误差大，配准率低的问题，提出一种尺度和方向改进的ORB特征匹配算法。该算法以二进制描述算法ORB为基础，构建金字塔式尺度空间，改进尺度空间结构，简化尺度空间层数和采样图像数目，使提取特征点的过程更加效率，并采用Harris函数检测特征，消除边缘特征点的影响，提取具有尺度信息的特征点；然后采用梯度方向统计方法改进传统ORB算法中通过灰度质心法计算主方向的方式，优化求解主方向邻域范围，以提高图像特征主方向的准确性。实验结果表明，改进后的ORB算法在尺度和旋转配准方面性能有很大提高，并且配准的精度较传统ORB更高，更能满足复杂图像快速精确配准的要求。     

基于ORB-LATCH的特征检测与描述算法

针对基于学习安排的三元组（LATCH）二进制描述子不具备尺度不变性且其旋转不变性,需要特征检测子辅助的问题,提出了一种基于快速定向旋转二进制稳健基元独立特征（ORB）和LATCH相结合的特征检测与描述算法。首先,在图像金字塔尺度空间上进行加速段测试特征（FAST）检测;然后,采用ORB灰度质心方法来进行方向补偿;最后,对特征进行LATCH描述。实验结果表明,所提算法具备运算量小、实时性高以及旋转和尺度不变性的特点,在相同的准确率下,其召回率优于ORB和哈里斯-LATCH （HARRIS-LATCH）算法,其匹配内点率比ORB算法提高了4.2个百分点。该算法在保持实时性的同时进一步缩小了与基于直方图的尺度不变特征变换（SIFT）和加速健壮特征（SURF）算法之间的精度差距,可对图像序列进行快速且精确的实时处理。     

基于中心环绕滤波器检测的图像特征点匹配算法

针对传统图像匹配算法特征点检测稳定性和准确性差的问题,提出一种尺度不变性的基于中心环绕滤波器检测（SCFD）的图像特征点匹配算法。首先,构建多尺度空间,利用中心环绕滤波器检测图像在不同尺度下的特征点,采用Harris方法和亚像素插值获得稳定的特征点;其次,联合快速定向旋转二进制稳健基元独立特征（BRIEF）（ORB）算法确定特征点的主方向,构建特征点描述算子;最后,采用汉明距离完成匹配,通过最小平方中值（LMedS）定理和最大似然（ML）估计剔除误匹配点。实验结果表明,在尺度变化时,所提算法的匹配精度达到96.6%,是ORB算法的2倍;其运行时间是尺度不变特征变换（SIFT）的19.8%,加速鲁棒性特征（SURF）的28.3%。所提算法能够有效提高特征点检测的稳定性和准确性,在视角、尺度缩放、旋转、亮度等变化的情况下具有较好的匹配效果。     

一种基于四叉树的改进的ORB特征提取算法

文中提出了一种基于四叉树的改进的ORB(Oriented FAST and Rotated BRIEF)特征提取算法,它能够解决图像特征提取过程中特征点过于集中而导致的图像局部特征信息丢失的问题。首先,将图片构造成图像金字塔来解决尺度不变性问题;然后,在每一层金字塔图像上检测角点来提取特征点;接着,引入四叉树算法来 均匀化分布特征点并计算特征点的方向和描述子;最后,以华硕深度摄像头(Xtion PRO)为实验工具,在室内环境下提取周边特征点,并将提取效果与其他方法进行对比,实验证明了所提算法在图像特征均匀化处理方面的快速性以及准确性。     

基于显著图的输电线路杆塔图像拼接方法

无人机拍摄的输电线路杆塔图像分辨率高且背景复杂,基于传统特征点的拼接算法在背景中检测出大量的特征点增加了图像匹配的时间,影响了杆塔的匹配精度。针对该问题提出了一种既稳定又具有较小时间开销的输电线路杆塔图像自动拼接方法,利用改进的显著性检测算法得到杆塔图像的显著图,将图像的前景与背景分离,减少了背景对图像中杆塔拼接效果的影响;并采用基于定向的加速分割检测特征(FAST)和旋转不变性的二进制鲁棒独立元素特征(BRIEF)描述子(ORB)特征点的图像匹配算法,以提高特征点提取和匹配的速率;最后利用多尺度融合策略得到最终的拼接结果。实验结果表明,所提方法具有较好的拼接效果和拼接效率。     

海浪绘制中波浪谱的选择和参数计算

针对红外与可见光图像中特征点匹配的难题,提出一种基于特征点邻域边缘的描述与匹配算法。首先采用基于曲率尺度空间的角点检测算法进行特征点提取;再对特征点邻域的边缘进行重组;其次求取特征点所在曲线的法线作为主方向,以避免图像的旋转代价;计算特征点邻域像素点的B-LBP算子的加权分布直方图;然后搜索相同边缘上最近的特征点并计算相应的直方图信息;再对两个直方图进行级联,构造出512维的UB-LBP联合描述子,并将其归一化;最后采用最近邻算法实现特征点匹配。实验结果表明,这两种描述子在红外与可见光图像特征点匹配方面较SIFT算法具有较高的正确匹配率,能够实现两种图像的精确匹配。     

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。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.