可抗噪声的Canny改进边缘检测算法

由于图像噪声的存在,传统的边缘检测算法常常无法准确检测到边缘信息.本文分析了噪声条件下边缘信息的几何特征,提出一种基于几何边缘增强技术的边缘检测算法.首先采用Canny算子计算图像的初始边缘信息,然后根据初始边缘信息自动计算阈值排除弱边缘,对剩余边缘计算带方向梯度值进行增强,根据增强边缘信息自动计算双阈值,最后用双阈值方法检测、过滤并连接边缘.该算法提高了边缘检测的准确性,可以高效率地处理噪声和纹理导致的虚假边缘.     

基于小波尺度积的图像边缘检测算法

图像边缘检测技术是图像处理中最重要的内容之一,针对噪声大、灰度对比度低的图像,利用小波尺度乘积模极大值对其进行边缘检测.在进行二进小波变换后,先把相邻尺度的小波系数直接相乘,抑制噪声和增强图像边缘信息,再运用模极大值检测图像边缘,利用隶属函数确定阈值.该算法可以免除传统小波模极大值边缘检测后繁杂的边缘链接,简单易实现,实验证明其对抑制噪声和增强弱边缘有良好的效果.     

基于模糊参数的高斯边缘检测模型方法研究

对图像边缘提取的问题进行了研究,针对以往边缘提取算法容易造成边缘断裂,提取较多噪声的缺点,提出一种利用模糊逻辑函数在全局上对图像进行增强,在局部进行边缘提取的算法。定义一个模糊逻辑函数,利用类似直方图均衡化的方法,对变换后的模糊逻辑图像进行对比度增强操作;在增强的图像上,对模糊逻辑函数进行局部非线性投影变换,并在变换基础上进行边缘图像的阈值检测,从而得到最终的边缘图像。在进行非线性变换的同时,利用梯度迭代法对非线性参数进行优化,从而保证获得最优的高斯模型,并提取出边缘信息。该方法在自动获得最优的系统参数同时,能准确有效地提取出图像的边缘,克服噪声对系统的干扰;并能广泛使用在基于边缘信息的图像处理系统和模式识别系统中。     

带细节增强与降噪的真彩图像多尺度边缘检测

为了解决真彩图像降噪和边缘细节保留的问题,提出了使用一种软阈值方法进行细节增强与降噪的真彩图像多尺度边缘检测算法。使用小波多尺度真彩图像边缘检测算法得到不同尺度边缘图像,进而根据改进的软阈值滤波函数,对得到的边缘图像进行阈值选择,降噪的同时也增强了保留的边缘细节信息;最后对不同尺度边缘图像进行了加权二范数融合。实验证明,该算法能充分利用真彩图像的颜色和梯度信息,有效地抑制噪声,增强图像的细节信息。     

结合小波滤波和形态学的图像边缘检测方法

针对传统的边缘检测方法对含噪图像检测效果不理想,提出了一种小波滤波和多结构元素的数学形态学相结合的图像边缘检测方法。用广义交叉验证准则进行小波阈值的自适应选取,用此阈值的广义阈值函数的小波滤波方法对含噪图像去噪;构造4种具有代表性的结构元素,根据边缘方向自动选择相应方向的结构元素,用改进的形态学边缘检测算子对图像进行边缘检测,得到在噪声存在条件下较为理想的图像边缘。实验结果表明,该算法能够有效地抑制噪声,检测的边缘较清晰、连续,其检测效果优于传统边缘检测算法。     

去除磁共振成像图像莱斯噪声的加权扩散

针对各向同性扩散易于造成图像边缘等特征区域的模糊以及相干增强扩散易于在图像背景区域内产生伪条纹的问题,提出了一种根据磁共振成像（MRI）图像莱斯噪声分布特点来对其进行降噪的加权扩散算法。该算法以MRI图像背景区域的莱斯噪声方差作为区分MRI图像背景区域和感兴趣的边缘特征区域二者特征差异的阈值。基于该阈值,该算法构造了一个加权函数,并用该函数对各向同性扩散和相干增强扩散进行加权。加权函数根据图像在不同结构区域的变化,自适应地调整两种扩散的权值,从而充分发挥两种扩散的优势并克服各自的不足。实验结果表明,该算法在峰值信噪比（PSNR）及平均结构相似度（MSSIM）的评价上优于一些经典算法。因此,该算法的降噪及保护、增强边缘的能力更为优越。     

基于引导滤波和Tsallis熵的SAR图像分割算法

针对合成孔径雷达(SAR)图像易受噪声干扰、分割方法精度低的问题,提出了一种基于频域引导滤波和Tsallis熵的SAR图像多阈值分割算法.利用非下采样Contourlet变换(NSCT)对图像多尺度分解,提取图像各方向的高频信息;通过引导滤波增强高频分量的边缘信息,在保持边缘的同时抑制了相干斑噪声;利用改进的二维Tsallis熵多阈值对增强图像精确分割.实验结果表明:分割算法对噪声不敏感,分割精度和适应性明显提高.     

基于图像特征方向的PDE去噪方法

基于PDE的非线性扩散滤波方法对接近高斯分布的噪声可以取得较好的效果,但对脉冲噪声效果不是很理想.文中应用了基于图像特征方向的正交坐标系,使噪声消除具有了方向性,并提出了新的扩散系数函数,改变了图像边缘阈值,使其能在消除高梯度图像噪声的同时保持了边缘,在一定程度上解决了边缘保持和噪声消除之间的矛盾.     

适用于汽车油箱盖的边缘检测方法

为从带有噪声、高反光区域、灰尘覆盖和涂鸦等情况的汽车油箱盖图像中精确提取边缘,设计一种适用于汽车油箱盖的边缘检测方法.提出一种基于伪球与内积能量的改进Canny边缘检测方法,对Canny算子在滤波、梯度计算及阈值选取方面进行改进,用于获取精细边缘;设计一种基于形态学与Otsu阈值算法的油箱盖粗边缘检测方法,用多尺度底帽变换对图像进行增强并用Otsu阈值算法进行分割,用形态学方法获得油箱盖粗边缘;将粗边缘与精细边缘进行"与"操作得到油箱盖的边缘.仿真结果表明,提出算法能精确提取出汽车油箱盖边缘.     

基于改进小波阈值法的图像去噪算法

图像去噪是图像处理中最基本、最重要的前期工作,本文提出一种基于衰减法的Garrote阈值函数,并将基于该改进阈值函数的小波阈值法用于图像去噪过程,最后通过MATLAB仿真实验验证了本文所提出算法的有效性.本文在分析小波阈值法对图像去噪效果影响的基础上,针对该去噪算法在去除噪声的同时也损失了一定量的图像细节信息的问题,改进了传统阈值函数未考虑阈值以下的小波系数可能含有图像细节信息而对阈值以下小波系数盲目置零的缺点,对Garrote阈值函数阈值以下的小波系数采取衰减方法,以保留更多的图像细节信息,并加入三个调整因子以提高其性能和灵活度,实验表明本文提出的改进小波阈值去噪算法能够有效地去除噪声,且能够保留大量的图像边缘及细节信息.     

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.