基于累加梯度和PCA变换的图像融合算法

为了从不同源图像获取互补信息,获得一幅比任何源图像更准确、全面、可靠的复合图像,提出了一种基于局部累加梯度和PCA变换的图像融合算法.该算法在对源图像进行双树复小波变换的基础上,运用局部累加梯度准则实现融合图像的局部细节系数选取,运用基于PCA变换的选择或平均准则实现融合图像的局部逼近系数选取,并对获得的融合细节系数和逼近系数进行双树复小波反变换得到相应的融合图像.通过计算机仿真,从视觉效果和定量分析可以看出该图像融合算法是有效的.     

一种有效保留图像细节的自适应图像消噪方法

针对更多保留图像细节信息有效滤除噪声的问题,分析了双密度双树复小波的变换原理及特点,推导了双变量萎缩函数,提出一种基于双密度双树复小波变换的局域自适应图像消噪算法。首先对含噪图像进行双密度双树复小波分解;后根据小波系数的统计特性以及层内和层间系数的相关性,采用结合局域方差估计的双变量萎缩函数对小波系数进行处理,并用处理后的小波系数重构图像。实验结果表明：该算法在滤除噪声的同时可保留更多的图像细节,极大地改善了图像的视觉质量。     

采用双树小波变换的医学图像融合方法及实现

双树小波变换具有平移不变性及良好的方向性,将其引入到医学图像融合能够较好地提取原始图像的特征,为融合图像提供更多的信息.提出基于双树小波变换的医学图像融合算法,该算法对图像进行多尺度和多方向的分解,在相应尺度上利用融合算法融合,最后进行重构得到融合结果.通过实验仿真及客观的图像融合评估准则,实验结果表明了双树小波分解能够得到比树状小波分解更好的融合效果,信噪比提高了很多,均方差明显减少,充分保留了图像中的细节信息,减少了融合的复杂度.     

基于DTCWT方向信息的超声图像斑点噪声消除

针对一般的小波去噪方法在去除超声图像斑点噪声时不能有效保持图像边缘信息的问题,本文提出基于双树复小波变换(Dual tree complex wavelet transform,DTCWT)方向信息的超声图像斑点噪声消除算法.利用双树复小波变换6个方向复小波系数的相对方差来确定该点是否位于边缘或纹理上,对低于门限的像素...     

基于双树复小波的遥感图像融合

介绍了DTCWT(双树复小波变换)的基本原理,与传统小波变换相比,DTCWT具有良好的平移不变性和方向选择性,能够提高小波分解和重构的精度,更好地保持边缘、纹理等细节.在传统小波图像融合的基础上,提出了三种基于DTCWT的遥感图像融合算法:基于IHS变换和DTCWT融合法、模值加权融合法和模值局部方差融合法.对"北京一号"小卫星数据进行融合实验,结果表明,三种融合算法不仅有效地增强了融合图像的空间细节表现能力,而且很好地保留了多光谱图像的光谱信息.     

基于对偶树复小波域图像融合的SAR图像去噪

边缘信息是图像重要的细节信息,保护图像的边缘信息对提高图像质量非常重要.但是在图像去噪的过程中,往往会破坏图像的边缘信息.针对去除噪声和保护边缘信息的双重考虑,提出一种基于对偶树复小波域图像融合的SAR图像阈值去噪.考虑到局部硬阈值和软阈值各自的特点,利用对偶树复小波变换的优点和图像融合的特点,首先在自然对数域对SAR图像进行对偶树复小波分解,然后对小波系数分别执行局部硬阈值去噪和局部软阈值去噪,最后依次通过图像融合,对偶树复小波反变换,指数变换得到去噪以后的图像.实验结果表明,算法融合了两种周值去噪方法的优点,在明显去噪的同时,更好地保护了图像的边缘信息.     

双密度双树复小波域多聚焦图像融合

将双密度双树复小波变换引入多分辨率图像融合中,利用双密度双树复小波变换的多尺度、多方向性和平移不变性特征分解多聚焦图像,对分解后高、低频图像系数采用不同融合策略进行融合,应用双密度双树复小波逆变换重构图像。采用多组多焦距源图像进行融合实验,并对融合结果进行了客观评价。实验结果表明双密度双树复小波域融合方法对多聚焦图像具有更好的融合效果,图像的细节描述更加精确。     

基于小波变换和曲波变换的图像边缘检测新算法

针对图像处理中的边缘检测问题,提出了一种基于小波变换和曲波变换的图像边缘检测新算法。首先对原始图像进行小波变换得到小波边缘图像;然后对原始图像进行曲波变换并使用Canny算子得到曲波边缘图像;最后基于小波变换的窗口内边缘强度自适应融合算法将小波边缘图像和曲波边缘图像进行融合得到最终边缘图像。该方法结合了小波变换描述图像细节特征的优势和曲波变换处理曲线或直线边缘特征的优势,能全面刻画边缘图像的纹理与细节信息,提高了图像清晰度。仿真实例表明了该算法的有效性。     

基于冗余小波变换与引导滤波的多聚焦图像融合

针对传统多尺度变换在多聚焦图像融合中存在的边缘晕圈问题,提出了一种基于冗余小波变换与引导滤波的多聚焦图像融合算法。首先,利用冗余小波变换对图像进行多尺度分解,将源图像分解为一个相似平面和一系列小波平面,该多尺度分解能够有效地提取源图像中的细节信息;然后,对相似平面和小波平面分别采用引导滤波的加权融合规则来构造加权映射,从而得到相似平面和小波平面的加权融合系数;最后,进行冗余小波逆变换,即可得到融合结果图。实验结果表明,与传统融合算法相比,所提算法能够更好地体现图像边缘的细节特征,取得了较好的融合效果。     

基于Sobel算子的小波包变换遥感图像融合算法

针对遥感图像融合时图像的空间信息与光谱信息不易兼容的问题,在小波包变换的基础上提出了一种基于Sobel算子的图像融合算法。该方法将多光谱图像与高分辨率图像进行小波包变换,根据阈值选用不同的融合准则得到小波低频系数,利用Sobel算子提取图像高频特征值,采用最值法获取高频系数。实验结果表明,所提算法优于传统的HIS(Intensity,Hue,Saturation)变换、小波变换以及两者结合的方法,在较好地保留图像光谱信息的同时,进一步增强图像的细节信息、边缘特征,从而提高图像的清晰度。     

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.