新的桶形畸变的点阵样板校正方法

为了校正广角镜头的桶形畸变,提出一种新的桶形畸变数字校正方法。它使用点阵样板校正的方法,根据畸变图和理想图中圆点的位置关系,得出畸变图像素在X轴和Y轴方向上的偏移量曲面,采用三次B插值函数对曲面插值;由曲面插值获取像素点的偏移量,对各像素进行坐标转换得到校正图像;然后对图像进行了双线性插值的灰度重建。仿真结果表明,该方法使图像的坐标位置和灰度都得到很好的校正。     

基于加速鲁棒特征的广角图像自动拼接校正算法

广角图像在全景图拼接中优势明显,然而,由于广角图像存在严重的透视畸变,往往导致拼接的效果不理想,甚至导致拼接失败。针对广角图像拼接中的透视畸变问题,提出一种广角图像自动拼接、校正算法。先计算出待拼接广角图像的特征点匹配对,求出图像拼接矩阵,对广角图像进行拼接;然后,根据图像采集时的镜头旋转角度计算出图像校正矩阵,对拼接后的全景图进行透视畸变校正。实验结果表明,基于该算法得到的全景图能够有效地消除透视畸变,达到较好的拼接效果。     

基于非线性样条插值的大广角相机畸变校正方法

针对现有的棋盘格检测方法只能检测规则的棋盘格的问题，改进了基于生长法的棋盘格检测和匹配部分,使其能够生长出非规则的棋盘格，以增加棋盘内角点数据。针对目前大广角相机广角方向及复杂镜片的畸变校正方法存在精确性问题，提出了使用薄板样条(thin-plate spline)和双简谐(biharmonic)插值算法来解决畸变的方法。该方法通过散乱的多个数据点进行控制，使其趋近数据点目标值，从而拟合出映射曲面达到去畸变的目的。实验结果证明了该方法的可行性和鲁棒性，提高了复杂畸变和广角相机畸变在广角方向上的校正精度。     

基于图像平面的畸变校正方法

针对图像液位检测系统中摄像头引入的图像畸变,提出一种基于图像平面的校正方法。使用虚拟的标准校正图代替实际图,通过二阶径向模型的反复迭代求取畸变系数,利用双线性插值对输出像素点灰度进行插补。实验结果表明,该方法的校正误差小于0.35个像素点,能有效提高视频检测精度。     

一种抗几何畸变的景象匹配方法

在分析景象匹配实时图获取过程中几何畸变产生原因的基础上,利用弹上高度传感器和姿态角传感器获取的图像高度和姿态信息,实现了畸变实时图的几何校正,给出了校正实时图大小和偏移量的确定方法,结合匹配计算和匹配结果修正,提出了一种抗几何畸变的景象匹配方法。仿真实验结果验证了该方法的有效性和实用性。     

一种改进的单目机器人立体视觉系统校正方法

基于三棱镜的单目立体视觉系统具有高集成度、低功耗、易装配等特点,但外置的棱镜也会引发不规则的图像畸变,影响成像质量。首先采用双边滤波函数对目标图像进行降噪处理,增强图像中的边界,有效提高标定图像中的特征点提取的准确性;然后结合透视投影中的直线性、交比一致性和没影点收敛性等投影不变性提出一种改进的自适应畸变校正算法。该算法无需畸变模型及畸变参数,通过校正前后特征点的偏移,最终得到畸变校正所需的像素位移图。实验对比了多组图像的特征提取效果和畸变校正结果,并比较了不同校正方法对于系统中产生的不规则畸变的校正效果,结果表明该算法具有鲁棒性和准确性,提高了机器人视觉系统的准确度。     

基于线性特征的鱼眼图像校正方法

针对鱼眼镜头采集的畸变图像,在棋盘格标定模板的基础上,提出一种有效的校正方法。该方法采用标准畸变模型,首先基于畸变图像的线性特征提出目标函数;然后利用SUSAN改进算法精确定位棋盘格角点坐标;对已得到的有限角点坐标进行畸变曲线拟合,在畸变曲线上提取所需数量的点;最后用渐近寻优算法计算最优畸变系数,使得目标函数最小。实验结果表明,该方法角点定位精确、算法时间复杂度低,能够有效校正鱼眼镜头造成的图像畸变。     

一种新的鱼眼图像校正算法

鱼眼镜头由于焦距短视角大而在不同领域得到广泛应用,但鱼眼镜头在成像时由于不同视场垂轴放大率不同,使图像产生畸变,影响鱼眼图像的实际应用价值,由此引起了人们对鱼眼图像的研究热潮。该文就校正鱼眼图像畸变问题展开研究,首先提出了一种新的确定鱼眼图像有效区域的扫描线逼近算法,解决了经典扫描线逼近法在有效区域边界存在大量黑色像素点时容易出现偏差的问题。然后,又提出了一种对鱼眼图像横向和纵向同时进行校正的算法,实验结果表明新的校正算法的横向校正效果与经度校正算法相近,纵向校正效果明显优于经度校正算法,在校正速度上也有所提升,且校正后的图像清晰度要远远好于经度校正算法校正后的图像。     

基于图像畸变校正的车轮踏面区域提取

为了实现踏面缺陷部位面积的精确测量,提出了一种基于图像畸变校正的车轮踏 面区域提取方法。首先采用改进的彩色图像标记分水岭初次分割侧视视角踏面曲面图像,然后 根据踏面曲面图像横向和纵向畸变的不同特点顺次进行平面横纵坐标几何校正并在此过程中完 成踏面区域的二次分割与视角转换,最后得到踏面正视视角矫正图像。实验结果表明,该方法 可以准确分割并校正侧视视角踏面图像,为实现踏面缺陷面积的精确计算打下基础。     

鱼眼畸变棋盘格图像校正

畸变棋盘格图像能够更精确地描述鱼眼镜头的畸变特征,畸变棋盘格图像校正算法的研究对实现畸变图像准确快捷的校正具有重要意义。在研究Carroll等人提出的校正方法的基础上,针对畸变的棋盘格图像提出了一种简单、快捷的校正方法。以棋盘格的角点坐标替代直线特征信息作为校正模型的输入,对建模后的目标函数进行线性优化求解。该方法实现了畸变校正的自动化,提高了系统的效率。实验表明,该方法方便可行,校正结果良好。     

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.