基于平移不变小波变换的图像融合技术的实现

本文介绍作者所进行的基于像素级图像融合技术的研究。目前,图像融合技术主要分为像素级、特征级和决策级这三种主要方法,而像素级图像融合的方法可以更多地保留原有图像的信息,并对单一像素信息进行处理,精度高、方法简单易行,目前被广泛的应用在各个领域。而基于平移不变小波变换算法先对待融合的多源图像进行空间域的变换,得到图像各层分解后的系数,再对该组系数按一定的融合规则进行融合处理得到一个融合后的系数表示,最后经图像的逆变换获得最终的融合图像。     

基于小波变换的遥感图像融合方法研究

本文提出了基于小波变换的图像融合过程中最关键的步骤是系数的融合,对系数融合的方法做了深入的探讨和归纳。针对多遥感器图像融合,因涉及到不同的数据源,其数据获取方式,图像融合方法十分不同,很难有一个具体模型的情况,提出了基于弹性模型的方法。     

一种基于快速Curvelet变换的图像融合新算法

提出一种基于快速Curvelet变换的图像融合算法,针对Curvelet变换后的不同频率域,分别讨论了低频系数和高频系数的选择原则。     

基于移不变形态中点小波的多聚焦图像融合

为解决不同聚焦深度下多幅图像的信息融合问题,提出一种变换域处理方法。首先基于非线性的中点滤波器,以非抽样方式构造出具有移不变性的形态中点小波变换。然后对形态中点小波变换进行提升,从而改善算法性能。最后,利用提升后的形态中点小波分解待融合图像,选取合适的融合规则处理变换域系数,通过反变换重构得到融合后的图像。计算机仿真实验表明,移不变形态中点小波多分辨率分析方法能有效融合多聚焦图像,与传统线性小波变换或其他较流行的小波变换相比,得到的整个场景更加完整清晰。     

基于边缘和局部能量的NSCT变换遥感图像融合

对基于边缘的算法进行了改进,综合考虑了边缘和能量结构. 首先利用非下采样contourlet(NSCT)变换,对图像进行多尺度和多方向的分解;然后将低频系数按边缘能量大小划分为边缘和平滑2部分,边缘部分采用边缘能量取最大的融合方法,平滑部分使用基于局部能量的规则进行融合,高频子带使用相关系数和局部方差相结合的重要性测度法进行融合;最后对融合系数进行NSCT反变换得到融合图像. 实验结果表明,该算法融合效果较基于边缘算法有所改善,是一种有效兼顾细节和能量结构的方法.     

基于人眼视觉特性的分形小波包图像编硒压缩技术研究

针对图像能量分布特点及人眼对图像特殊区域敏感程度的不同,提出利用小波包对图像的低频子带和高频子带都进行多分辨率分解,并充分利用人眼的视觉特性和不同子带间小波包系数的相关性对系数进行分形编码。实验结果表明在保证优先编码视觉上最重要系数的同时,能够进一步提高图像复原质量。     

一种改进的红外与可见光图像融合方法

针对传统图像融合方法存在的细节不突出、轮廓模糊等问题,设计了一种改进的红外和可见光图像融合方法。采用非采样Contourlet变换将源图像分解为高频和低频子带系数。提出了一种基于几何与能量距离加权的低频子带系数融合策略以及基于灰度差异与梯度距离加权的高频子带融合策略。经过NSCT逆变换得到融合后图像。最后,进行实验研究。结果表明:所述方法不仅能够较好地保持低频子带的能量信息而且可以有效地提取高频子带的细节特征;融合结果比较理想。     

红外辐射检测及其图像融合技术

本文首先分析了红外辐射无损检测实验系统的原理及组成部分,进而通过对实验系统设置不同的参数,得到一系列红外无损检测成像的相关实验数据,描述了由于参数设置的不同,导致的不同检测结果。在此基础上,为了增加图像的辨识能力及信息含量,进一步研究了红外无损检测图像融合技术改进的几种算法,通过对像素融合法、区域融合法、对比度调制法、透明度融合法等几种图像融合技术算法的介绍,提高了红外辐射无损检测图像的缺陷辨识能力,为提高检测的灵敏度和可靠性提供理论技术支持。     

基于MATLAB的图像融合技术

在数字图像处理高速发展的今天,在计算机视觉、医学图像处理、红外检测、遥感影像分析和机器人视觉等诸多领域都用到了"图像融合"技术,而且很适合当今科技发展的潮流。图像融合通常分为特征级、像素级以及决策级三个层次。图像融合技术作为当下信息技术的一个重要领域,是将来自不同时间、不同源、不同介质、不同表达方式、不同媒介的图像数据按一定的标准和规则综合在一起,以形成对图像目标更为清晰、完整、准确描述的图像处理技术。但是"图像融合"这一词汇对于初学者还是比较生僻的,所以本文在此具体地剖析讲述一下基于MATLAB的图像融合技术,以便于初学者能够理解比较复杂的数字图像处理技术和内容,如果大家能够拓展和举一反三,其他的数字图像处理技术也会很轻易地理解并掌握。     

遥感图像融合技术探讨

对图像融合的原理和方法进行了剖析,研究和分析了几种常用的多源遥感图像融合的方法:Brovey法、主成分分析和乘积法等,并以实例对这三种方法融合的图像进行了评价.     

To serve and promote science development via innovation

CAS should stick to the principle of rendering service to, and giving impetus for, the development of China＇s science enterprise by making S＆T innovations, said CAS President LU Yongxiang. The CAS president made the remarks in a recent talk to communicate the gist of the winter session of the Party＇s Leading-member Group at CAS, which was held from 7 to 11 January in Beijing.     

Students' Reactions to the Introduction of Videoconferencing for Classroom Instruction

This study examined how students who had no prior experience with videoconferencing would react to the use of videoconferencing as an instructional medium. Students enrolled in seven different courses completed a questionnaire at the beginning of the semester and again at the end of the semester. Students at the origination and remote sites did not differ in their reactions toward videoconferencing but there was a significant difference for gender. Women reacted less favorably to videoconferencing. Compared to the beginning of the semester, students reported significantly less positive attitudes toward taking a course through videoconferencing at the end of the semester. There were no significant differences in students' attitudes toward videoconferencing across courses at the beginning of the semester but there were significant differences across the courses at the end of the semester. The results suggest the need for better preparation for both students and instructors.     

Tracing the origin and early radiation of birds——Paleornithologist ZHOU Zhonghe

With great care, Dr. ZHOU Zhonghe takes out a package wrapped by cotton tissue from a drawer and says: "This is the gem of our collections: the fossil of a bird that lived 125 million years ago!" Then, pointing at a tiny mound, he explains: "Look, this is the claw and that is the head. It was in the egg shell and ready to hatch ... The species fell into a family of waterside inhabitants."     

Cooler temperatures inductive to locust outbreaks

Ajoint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology and his co-workers from Norway, US and Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells, suggesting that China＇s projected climate warming could decrease the pest＇s numbers. The study was published in Proceedings of theNational Academy of Sciences on 17 September, 2007.     

Exploring Multiplexity: Social Network Structures in a Computer-Supported Distance Learning Class

A computer-mediated group is a complex entity whose members exchange many types of information via multiple means of communication in pursuit of goals specific to their environment. Over time, they coordinate technical features of media with locally enacted use to achieve a viable working arrangement. To explore this complex interaction, a case study is presented of the social networks of interactions and media use among members of a class of computer-supported distance learners. Results show how group structures associated with project teams dominated who communicated with whom, about what, and via which media over the term, and how media came to occupy their own communication niches: Webboard for diffuse class-wide communication; Internet Relay Chat more to named others but still for general communication across the class; and e-mail primarily for intrateam communication. Face-to-face interaction, occurring only during a short on-campus session, appears to have had a catalytic effect on social and emotional exchanges. Results suggest the need to structure exchanges to balance class-wide sharing of ideas with subgroup interactions that facilitate project completion, and to provide media that support these two modes of interaction.     

The Role of Intermediating Institutions in the Diffusion of Electronic Data Interchange (EDI): How Industry Associations Intervened in Denmark, Finland, and Hong Kong

Electronic data interchange (EDI) provides means for interorganizational communication, creates network externalities, requires an advanced information technology (IT) infrastructure, and relies on standards. In the diffusion of such innovations, institutional involvement is imperative. Such institutions contain governmental agencies, national and global standardization organizations, local government, and nonprofit private organizations like industry associations. The last type of organizations we call intermediating institutions. They intermediate or coordinate ("inscribe") the activities of a group of would-be adopters. Unfortunately, little is known of how these organizations shape the EDI diffusion trajectory. In this article we examine one specific type of intermediating organizations?industry associations?and how they advanced the EDI diffusion process in the grocery sectors of Hong Kong, Denmark and Finland. We identify six institutional measures, placed into a matrix formed by the mode of involvement (influence vs. regulation) and the type of diffusion force (supply push vs. demand pull), that can be mobilized to further the EDI diffusion. Industry associations were found to be active users of all these measures to varying degrees. Their role was critical especially in knowledge building, knowledge deployment, and standard setting. Furthermore, institutional involvement varied due to policy and cultural contingencies and power dependencies.     

How Electronic Publishers are Protecting Against Piracy: Doubts About Technical Systems of Protection

The increasing prospects of digital piracy has prompted the perceived need by electronic publishers to adopt technical systems of protection, and governments to reform their copyright laws. This article is a preliminary study of the management of intellectual property by electronic publishers, defined as those involved in the production of online databases, and CD-ROMs. It focuses on three main issues: (1) how electronic publishers view the increasing threat of piracy; (2) the methods of protection employed to protect intellectual property in digital format; and (3) the importance of technological protection of intellectual property in electronic publications. The analysis is based on a sample of 23 UK electronic publishers. The interviews revealed an interesting assortment of protection methods and did not show that technological protection was a preferred way. Instead, the means of protection, in addition to copyright law, comprised niche markets, pricing, trust, bad publicity, and nontechnical and technical means.     

Rough Justice: A Statistical Assessment of ICANN's Uniform Dispute Resolution Policy

Long-standing conflict between domain name registrants and trademark holders prompted the Internet Corporation for Assigned Names and Numbers (ICANN) to create a global, mandatory arbitration procedure known as the Uniform Dispute Resolution Policy (UDRP). The UDRP has been used in 2166 cases involving 3938 domain names as of 1 November 2000. The policy gives the initiator of a complaint, generally a trademark holder, the right to choose which ICANN-accredited dispute resolution service provider (RSP) will handle the case. During the preparation of the UDRP,some feared that complainant selection would lead to "forum shopping" that might bias the results. This article performs a statistical assessment of the forum-shopping thesis and finds support for it. There are statistically significant differences in the various RSPs' propensity to take away names from defendants; there are also major differences in the number of cases brought to each RSP. RSPs who take away names have the larger share of cases. The study examines other variables that might explain differences in market share, such as price, the plaintiff's nationality, or the time taken to decide a case. It finds that nationality and time also are correlated with market share. The study concludes that shopping for a favorable outcome is an important factor in the UDRP.     

Prevalence of soft neurological signs in Chinese people

Prof. Raymond C.K. Chen, a neuropsychologist with the CAS Institute of Psychology, has made novel progress in his studies of schizophrenia. His work has been reported by a recent issue of Behavioural Neurology.     

Stern-Gerlach effect goes chiral

Prof. SUN Changpu from the CAS Institute of Theoretical Physics and coworkers from University of Basel in Switzerland have worked out a way --at least in theory --to split a beam of molecules according to their chirality. The technique involves passing the molecules through three different laser beams and is similar to the famous Stern-Gerlach effect, whereby a beam of atoms passing through a magnetic field is split in two according to the atoms＇ spin states （Phys. Rev. Lett. 99 130403）.