基于SIFT算法的数字图像大变形测量技术研究

提出了一种基于尺度不变特征变换（SIFT）算法的大变形测量方法。该方法首先精确地提取出变形前后两幅图像的SIFT特征点,然后生成每个SIFT点的特征描述子,并利用该描述子对SIFT点进行匹配,得到这两幅图像特征点对应的坐标,最后使用仿射变换求出全场位移和应变参数。将该方法运用到模拟散斑图像中,并与基于差分进化算法的DIC方法进行对比。实验结果表明,所提算法不仅能够克服传统方法在转角大于7°容易失效的问题,还可以以较高的精度和效率计算出形变参数。     

基于投影散斑的实时场景深度恢复

为了解决传统匹配算法重建散斑图像时在视差不连续区域误匹配较多的问题,提出一种在网格顶点处选择种子点、渐进增长的区域生长匹配方法,以完成散斑图像的深度信息恢复.针对传统区域生长方法种子点选取速度低、覆盖性差的问题,提出在网格顶点处选择种子点的快速定位方法;在生长策略方面,采用逐步放宽种子点选择标准和生长标准的方式,渐进地增长区域;为克服散斑图像亮度不均衡的问题,采用零均值归一化互相关算子作为相关测度算子,并针对该算子冗余计算较多的问题,运用积分图结合其改进计算公式加速计算,确保算法的实时性;最后插值细化视差图,并根据三角测量原理转化视差值为深度值.实验结果表明,该方法深度恢复结果鲁棒性强、速度较快.     

机载图像辅助导航实时匹配算法研究

针对机载图像匹配辅助导航系统的实时性和精度高的特点,提出了基于部分Hausdorff距离的粗匹配与基于广义点理论的精匹配相结合的匹配方法;该方法利用多尺度边缘检测提取机载图像的边缘特征,将参考图像和实时图的边缘特征进行粗匹配和精匹配,并做了仿真实验;实验结果表明,该算法优于与灰度相关和SSDA算法对比,并验证算法的有效性.     

一种用于松质骨变形测量的数字图像相关方法

针对松质骨这一类多孔材料,直接利用被测物体自身的微结构或纹理代替人工散斑标记,然后使用Matlab编写变形测量计算程序,尝试将数字图像相关方法 DIC(digital image correlation)应用于松质骨变形测量。生成模拟散斑图像对该算法程序的可行性进行模拟验证,再利用猪股骨制作压缩试件对整个变形测量方案进行实验验证。模拟验证和实验验证结果表明:利用松质骨自身微结构纹理作为标记并编写算法程序进行DIC变形测量的方案是可行的,该方案也可用于和松质骨具有类似微结构的其他多孔材料的变形测量中。     

基于散斑结构光编码的三维人脸重建方法研究

三维人脸信息获取通过三维相机和三维人脸重建算法进行三维人脸建模。真实环境中三维重建方法往往存在匹配误差较高、表面粗糙等问题。针对三维人脸重建中的问题设计一套三维人脸重建算法用以提高三维重建效果,通过向人脸投射散斑图案增强人脸纹理,改进ZNCC算法生成平滑的三维人脸模型。通过仿真实验验证了该算法可以得到较高精度的平滑三维人脸模型。     

基于全局二值特征描述子的三维CBCT图像快速匹配算法

三维图像拼接是通过锥束CT(CBCT)获取大尺寸物体完整的高分辨率三维图像过程中的关键技术之一,成为目前三维图像处理的一个新的研究方向.针对基于特征点的三维CBCT图像拼接技术中相似特征匹配正确率低、匹配过程耗时长的问题,提出一种基于全局二值特征描述子的三维CBCT图像快速匹配算法.首先对二值特征描述子BRIEF进行三维拓展,以适应三维图像;在此基础上加入全局描述子,增强特征描述子的独特性;在特征点匹配时,根据上述特征描述子的特点设计由粗到精的匹配策略,提高特征匹配正确率和效率.实验结果表明,该算法简单有效,可以在大量相似特征条件下提高特征点匹配的正确率,同时也显著提升了匹配速度.     

电子剪切散斑3CCD传感图像特征去噪优化检测方法

针对CCD(Charge-Coupled Device)光学传感器采集电子剪切散斑干涉图像特征由于散斑指数高、峰值信噪比低,导致剪切散斑图质量差、检测效果不佳的问题,提出一种电子剪切散斑3CCD传感图像特征去噪优化检测方法。该方法分析了电子剪切散斑技术在三维物体表面变形检测中产生问题的原因,采用3CCD图像传感器替代单CCD图像传感器,引入同态滤波降噪处理图像,设计一种相位干涉技术,结合Canny检测算法,实现电子剪切散斑去噪优化检测。实验结果表明,应用3CCD传感器结合去噪技术的电子剪切散斑智能检测方法,图像散斑指数更低、峰值信噪比更高、检测时间更短,分别为0.023 4、19.5 dB、16.2 ms,并且三维物体表面变形测量误差在0.09 mm内,该方法有效提高了图像质量,从而提高了实际应用价值。     

基于数字图像相关技术的封装器件非接触全场应变研究

针对半导体封装器件盖板受力拉脱这一问题,提出一种简便易行的获取极限应力及全场应变分布的方法,利用数字图像相关(DIC)技术,对变形前后的散斑图像进行对比分析,即可获得物体表面位移及应变分布,根据位移变化关系可进一步计算出垂直度偏差。实验研究表明,该方法为实际工程应用提供了高精度倒装芯片拉脱强度数据。     

新型三维形貌测量系统SIFT算法改进研究

将测绘领域的三线阵摄影测量原理应用于运动物体三维形貌测量,提出一种基于三线阵CCD的新型三维形貌测量方法。针对新型测量系统获取的三线阵CCD影像同名点匹配问题,研究了常用的影像匹配算法,并选用SIFT匹配算法。由于传统SIFT匹配算法处理大尺寸图像耗时长、提取匹配点数少等不足,对算法进行优化,并提出基于新型大尺寸三维形貌测量系统的匹配搜索策略,确定最优匹配阈值,最后通过对比实验进行验证。实验表明,改进的算法能够解决匹配影像视角变化等问题,缩短算法处理时间,增加匹配点数,提高算法性能。     

复杂场景下灰度图像的运动目标跟踪

提出了一种对复杂场景下灰度图像序列中运动目标分割和跟踪的新方法:首先,利用光流法分割出运动目标;然后,以mean shift算法为核心跟踪感兴趣的目标.跟踪过程中以目标灰度直方图为特征进行帧与帧之间的目标匹配,其匹配的相似度以Bhattacharyya系数来测量.算法中利用Kalman滤波器对运动目标在图像中的位置进行预测,不仅可以有效解决目标的暂时遮挡问题,而且可以缩小模式匹配的搜索范围,提高处理速度.实验结果和对实验相关数据的分析验证了该跟踪算法的有效性和实时性.     

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.