基于Gabor滤波的指纹图像增强

在指纹识别系统中,图像增强效果的好坏对特征提取及指纹鉴别的识别率具有决定性的影响.根据指纹图像具有方向性和频率的特点,把Gabor滤波器应用在指纹图像增强处理中.利用Gabor滤波器的方向选择和频率选择特性,把指纹图像的局部方向和脊线频率作为Gabor滤波函数的参数,然后把Gabor函数与纹理图像进行卷积,从而去除了噪声,达到了增强图像的目的.在算法设计上提高了运算速度,节省了运算的时耗.实验证明,算法工作稳定,效果好,具有很强鲁棒性.     

一种新型自适应指纹图像增强算法

针对Gabor滤波器在处理低质量指纹图像时增强效果不佳的缺陷,提出一种基于方向域和频率域的新型自适应Gabor滤波增强算法。该算法改进了指纹图像方向图和纹线频率的提取方法,通过计算图像方向一致性和平均纹线频率两个参数来共同自适应地调节Gobor滤波器变换窗的大小。实验结果表明：对于低质量指纹图像,该算法大大提高了方向图准确性,而且自适应Gabor滤波器在处理不同类型的指纹时更具优越性。     

指纹图像预处理的研究

对一种基于Gabor滤波的指纹图像增强方法进行讨论并加以实现。由于局部指纹纹线脊谷交错,近似平面正弦波,其傅立叶频谱具有明显的峰值,且峰值的方向和位置取决于纹线的方向和频率,因此采用具有良好方向和频率选择特性的Gabor滤波器可以实现较好的增强效果。在这种指纹图像增强方法中,关键是如何准确地计算指纹纹线方向和纹线频率。详细介绍指纹图像的预处理方法包括指纹图像的分割和增强,并给出增强算法的流程及实验结果。     

一种改进的指纹图像增强算法

指纹识别一般包括指纹采集、图像预处理、特征提取及特征匹配等步骤.其中图像预处理中的指纹图像增强是最关键的步骤,直接影响特征提取和匹配.论文针对指纹采集中存在的指纹图像局部模糊的问题,提出了一种改进的基于Gabor函数的指纹增强算法.该算法首先对指纹图像进行归一化处理,然后对指纹图像分成奇异区和非奇异区分别进行点方向和块方向的求取,最后用改进的Gabor滤波器对指纹图像进行增强.实践表明,该方法能提高指纹图像增强的效果和速度.     

基于Gabor滤波器的指纹图像快速增强

研究并实现了利用Gabor滤波器对指纹图像增强的算法。改进了指纹图像方向图和纹线频率的提取方法,同时也对Gabor滤波器的快速实现方法进行研究,首先把Gabor滤波器分解为多个不同方向上有着不同参数的一维高斯滤波器的组合,然后通过递归的方法分别实现这些高斯滤波器,最后实现了Gabor滤波器的快速算法在指纹图像增强中的应用。实践表明,该方法效果良好,速度快,能大幅度提高指纹图像质量。     

基于二值指纹图像的Gabor滤波增强算法

在指纹预处理过程中,Gabor滤波器对于图像的平滑和分割具有十分显著的效果。但是Gabor滤波器对纹线方向和频率十分敏感,通过处理灰度图像得到的二值图像存在着严重的特征点丢失和变化问题。采用相位差分二值化方法,使二值化过程不依赖Gabor滤波。提出了在二值图像上利用Gabor滤波器增强的方法,保留了Gabor滤波器连接纹线断线和滤除图像中噪声的优点,避免了Gabor滤波器对频率的敏感性问题,有效地提高了指纹特征的保持度。     

基于加博函数的指纹增强算法及其应用

指纹增强对于提高细节特征提取的准确率乃至整个自动指纹识别系统的性能实现都具有重要的意义.研究了基于加博(Gabor)函数的指纹增强算法,对纹线方向提取算法进行了改进,提出了一种纹线频率提取方法,给出了加博函数用于指纹增强的具体应用形式,以指纹图像的纹线方向和纹线频率为参数,使用加博函数实现了对指纹图像的增强处理,并使用南京大学活体指纹库中的部分典型低质量图像样本对算法性能进行了测试.实验结果表明,该算法对低质量图像具有显著的增强效果,增强后可以有效地降低指纹匹配的拒识率(false reject rate,简称FRR),处理速度和增强效果可以基本上满足在线自动指纹识别系统的需要.     

改进的基于Gabor滤波器的指纹增强算法

研究并实现了利用Gabor滤波器对指纹图像增强的算法。改进了指纹图像方向图和纹线频率的提取方法,增加了对特征点的额外处理,并研究了Gabor函数的具体应用形式。实践表明,该方法能大幅度提高指纹图像质量。     

基于融合的显微图像Gabor边缘提取算法

不同参数Gabor滤波器都具有各自的频率选择和方向选择特性,图像中纹理基元可以利用多个方向和中心频率Gabor滤波器组提取出来的频谱值来表示.据此提出一种适应于显微图像的Gabor滤波边缘检测算法.使用特定不同方向Gabor滤波边缘提取算子对图像进行边缘信息提取,获得不同方向上边缘特征信息,对其进行分析和融合提取图像边缘.运用该方法时所获不同方向的图像边缘进行自适应融合,获得的图像边缘较理想,模糊的边缘得到增强,并有效地消除了噪声.实验结果表明,该算法对显微图像处理有效,检测到的边缘清晰.     

一种改进的基于Gabor滤波的指纹增强算法

研究并实现了基于Gabor滤波器的指纹增强算法,对纹线方向提取算法进行了改进,获得了较准确的方向图。并改进了纹线频率的提取方法,有效地避免了Gabor滤波后在脊线中留下伪纹线和小孔的问题。同时也对滤波算法进行了优化,有效地减少了运算量。实验证明,该方法工作稳定,效果良好,鲁棒性强,对低质量图像具有显著的增强效果。     

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.