基于加权空间离群点度量的随机脉冲噪声降噪算法

针对排序统计类降噪算法在随机脉冲噪声（RVIN）图像降噪过程中,对图像边缘和细节部分噪声识别不够准确以及恢复比较模糊的问题,提出了基于加权空间离群点度量（SLOM）的脉冲噪声降噪算法WSLOM-EPR。该算法以优化的空间距离差为基础,引入图像邻域均值和标准差,建立反映局部边缘细节特征的噪声检测方法,提高边缘细节处噪声的识别精度;然后以精确检测结果为基础,优化保边正则（EPR）函数,提高算法的执行效率,并增强算法保留边缘细节的能力。仿真结果显示,WSLOM-EPR算法在40%到60%噪声密度下对噪声点的误检和漏检综合表现优于对比算法,且能在两者之间保持一个较好的平衡;降噪后的峰值信噪比（PSNR）好于对比算法中的大多数情况,且边缘细节在视觉上更加清晰连续。结果表明WSLOM-EPR算法提高了噪声检测精度,有效地保持了恢复图像的边缘细节信息。     

一种分类迭代保边缘图像去噪算法

针对图像处理过程中去噪与保边缘这一矛盾,提出了一种分类迭代保边缘的图像去噪算法。该算法充分考虑到不同密度的脉冲噪声产生的噪点分布特性,将噪声分为连续性噪声和非连续性噪声,采用大小不同的2~3个模板对原始图像迭代运算,进行噪声点恢复。利用该算法对添加有不同密度噪声的图像进行处理,结果表明,该算法在有效恢复噪声点的同时,能够很好地保留图像边缘细节信息,解决了传统算法存在滤波和保边缘的矛盾冲突,与传统滤波算法比较,该算法的峰值信噪比及去噪后图像与原图像的整体相似程度均优于传统算法。     

多阶导数自适应视频超分辨率重建

传统视频超分辨率重建算法在去除噪声的同时,很难有效保持图像边缘细节信息。针对该问题,构建了一种结合多阶导数数据项和自适应正则化项的视频超分辨率重建算法。在正则化重建模型的基础上,该算法对数据项进行改进,引入能更好描述噪声统计特性的噪声多阶导数,并利用去噪效果较好的全变分(TV)和非局部均值(NLM)正则化项对视频超分辨率重建过程进行约束。此外,为了更好地保持图像细节信息,采用区域空间自适应曲率差分算法提取结构信息,从而对正则化系数进行自适应加权。实验结果表明:在噪声方差为3时,与核回归算法和聚类算法相比,该算法重建视频主观效果边缘更加锐化,局部结构更加正确、清晰;重建视频的均方误差(MSE)平均下降幅度分别为25.75%和22.50%;峰值信噪比(PSNR)分别平均提升了1.35 dB和1.14 dB。所提算法能够在去除噪声的同时有效保持图像的细节特征。     

基于噪声检测的总变分去噪算法

对受高斯和脉冲混合噪声污染的数字图像去噪方法进行了研究,提出了一种基于噪声检测的自适应总变分(TV)去噪算法。提出的改进算法采用两步迭代框架实现:脉冲噪点检测和全变分图像恢复。第一步中,考虑到脉冲噪声污染的像素点不包含原图像有效信息,采用一种局部统计值,即邻域像素间的随机绝对差排序值(ROAD)估计出噪点的位置;第二步中,采用L2-TV方法进行去噪处理,并对上述过程进行迭代处理,得到去噪图像。在噪点估计过程中引入脉冲噪点水平参数,这样处理的优势在于可更准确地检测出脉冲噪点;而L2-TV去噪方法可很好地去除高斯噪声,两者结合有效地解决了TV算法存在误判图像脉冲噪声为边缘而产生假边缘的问题。与现有典型去噪方法的比较实验表明,该迭代去噪算法,即TV-ROAD算法,既能够去除混合噪声,又可以保留图像细节特征。     

自适应非局部数据保真项和双边总变分的图像去噪模型

针对常见去噪方法容易造成特定区域过度平滑、奇异结构残余噪声以及产生阶梯效应和对比度损失等问题,提出一种自适应非局部数据保真项和双边总变分的图像去噪模型,建立了自适应非局部正则化能量泛函和相应的变分框架。首先,对噪声图像利用自适应权值的非局部均值求得数据拟合项;其次,引入双边总变分正则化项,利用正则化系数来适度平衡数据拟合项和正则化项的影响;最后,通过能量函数最小化对不同的噪声统计快速求得最优解,从而达到降低残余噪声并纠正过度平滑的目的。通过理论分析和针对模拟噪声图像与真实噪声图像的实验结果表明,所提出的图像去噪模型能够较好地处理具有不同统计特性的图像噪声,与自适应非局部均值滤波去噪相比,所提算法的峰值信噪比（PSNR）值最多可以得到0.6 dB的改善;与全变分正则化图像去噪算法比较,所提算法的主观视觉效果明显更好,在去噪的同时图像纹理和边缘等细节信息保护得更好,PSNR值最多可以提高10 dB,而多尺度结构相似性度（MS-SSIM）指标可以提升0.3。因此,所提出的图像去噪模型可以在理论上更好地探讨如何合理处理噪声和图像内容本身的高频细节信息,在视频和图像分辨率提升等领域也具有良好的实际应用价值。     

基于压缩感知的自适应正则化磁共振图像重构

当前基于压缩传感理论的正则化磁共振(CS-MR)图像重构算法普遍采用全局正则化参数,不能很好地在保持边缘和平滑噪声方面做出平衡。为此,提出一种自适应的正则化CS-MRI重构算法。结合图像稀疏性和其局部光滑性的先验知识,采用非线性共轭梯度下降算法求取最优化问题,并在迭代过程中自适应地改变局部正则化参数。新的正则化参数可以更好地恢复图像边缘,并且有利于平滑噪声,使代价函数在定义域内具有凸性;同时先验信息包含于正则化参数中,以提高图像的高频成分。实验结果表明该算法能有效权衡恢复图像边缘和平滑噪声两者的关系。     

基于偏微分方程的舌图像去噪研究

在对舌图像的去噪过程中,平滑噪声的同时容易丢失边缘和纹理等细节信息。为此,研究基于偏微分方程的舌图像去噪方法,分别采用中值滤波、高斯滤波、P-M方程、正则化P-M方程以及耦合冲击-复扩散滤波模型,对加噪舌图像进行滤波。比较结果表明,正则化P-M方程更适合舌图像的去噪处理,该方法处理速度快、去噪效果好,且能有效保护图像边缘。     

基于概率统计模型与图像主纹理方向分析的非线性滤波算法

图像滤噪是图像预处理的一个重要内容,因为滤噪效果对图像处理的最终结果有很大影响。如何充分利用图像的局部特征以提高滤波器的滤噪效果、细节及边缘信息保持能力,在分析现有图像滤波算法的基础上,提出一种基于概率统计模型与图像主纹理方向分析的非线性滤波算法。算法利用Radon变换对图像进行主纹理方向分析,得到图像的局部纹理方向概率密度分布,然后基于概率统计模型借助中心像素的若干邻近像素对中心像素进行估计得到中心像素点的灰度值。此算法充分利用了图像的局部特征,既具有良好的去噪能力,又兼顾了对图像细节的保持特性。在处理同时感染脉冲噪声和高斯噪声的混合噪声图像时,算法效果明显优于其他滤波算法。     

改进的曲率滤波强噪声图像去噪方法

目的 医学影像获取和视频监控过程中会出现一些恶劣环境,导致图像有许多强噪声斑点,质量较差。在处理强噪声图像时,传统的基于变分模型的算法,因需要计算高阶偏微分方程,计算复杂且收敛较慢;而隐式使用图像曲率信息的曲率滤波模型,在处理强噪声图像时,又存在去噪不完全的缺陷。为了克服这些缺陷,在保持图像边缘和细节特征的同时去除图像的强噪声,实现快速去噪,提出了一种改进的曲率滤波算法。方法 本文算法在隐式计算曲率时,通过半窗三角切平面和最小三角切平面的组合,用投影算子代替传统曲率滤波的最小三角切平面投影算子,并根据强噪声图像存在强噪声斑点的特征,修正正则能量函数,增添局部方差的正则能量,使得正则项的约束更加合理,提高了算法的去噪性能,从而达到增强去噪能力和保护图像边缘与细节的目的。结果 针对多种不同强度的混合噪声图像对本文算法性能进行测试,并与传统的基于变分法的去噪算法（ROF）和曲率滤波去噪等算法进行去噪效果对比,同时使用峰值信噪比（PSNR）和结构相似性（SSIM）作为滤波算法性能的客观评价指标。本文算法在对强噪声图像去噪处理时,能够有效地保持图像的边缘和细节特征,具备较好的PSNR和SSIM,在PSNR上比ROF模型和曲率滤波算法分别平均提高1.67 dB和2.93 dB,SSIM分别平均提高0.29和0.26。由于采用了隐式计算图像曲率,算法的处理速度与曲率滤波算法相近。结论 根据强噪声图像噪声特征对曲率滤波算法进行优化,改进投影算子和能量函数正则项,使得曲率滤波算法能够更好地适用于强噪声图像,实验结果表明,该方法与传统的变分法相比,对强噪声图像去噪效果显著。     

基于PSO自适应正则化参数图像恢复的研究

图像恢复的根本目的是使降质图像趋向于复原或没有噪声影响的理想图像,当前的主要问题是如何在平滑噪声的同时保持图像的边缘和细节.文中提出了基于粒子群优化算法的自适应正则化参数图像恢复算法,与传统方法相比较,实验结果表明,文中方法在恢复效果上要优于传统的正则化方法、Lucy-Richardson 算法和维纳(Wiener)滤波器恢复,明显地克服模糊退化,同时也保护了图像的边缘等细节信息,图像纹路更加清晰,图像质量评价的ISNR好于传统方法.     

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。     

基于QTE的蒙古文显示机制研究与实现

蒙古语言是中国蒙古族使用的通用语言,由于蒙古文区别于其他文字的书写方式和其自身变形机制等特点,在很多通用的文字处理引擎中都不被支持。在嵌入式产品开发与应用领域中Linux加QTE已经成为流行方式。该文给出了一种在QTE环境上实现基于标准Unicode的蒙古文点阵显示和变形算法, 并自定义了支持蒙古文的QTE组件,扩展了QTE功能,为在Linux加QTE方式的嵌入式体系结构中处理蒙古文提供了一种解决方法。