海天背景图像去雾方法研究

海天背景图像存在大面积天空区域,且在远距离平视时目标一定出现在海天线附近,现有的去雾算法对天空区域的改善都是弱化天空区域的处理,这样势必会造成海天线附近去雾效果的减弱,不利于后续的目标检测.针对该问题,提出一种基于大气散射模型的图像复原去雾算法.首先,利用海天背景图像的特点,采用边缘检测算子将图像划分为天空和非天空区域,并结合大气光的物理意义,取天空区域最大的值作为大气光的估计值;其次,针对有雾图像对比度很低而无雾图像对比度较高这一先验信息设计代价函数,并通过SLIC超像素分割进行分块,通过求解每个小块内该函数的最小值,估计出粗透射率,再用引导滤波对粗透射率进行细化从而消除块效应;最后,利用大气散射模型,代入前两步求得的参数便可以得到恢复的无雾图像.实验结果与分析结果表明,本文能对海天背景的图像取得较好的去雾效果.     

结合天空区域识别的单幅图像去雾方法

针对现有图像去雾方法易于在天空区域引入负面视觉效果的缺陷,提出一个结合天空区域识别的单幅图像去雾方法;提出一个新的天空区域特征先验知识,并利用所提先验将雾天降质图像分割为天空与非天空区域;基于天空区域对大气光进行估计,并利用暗通道先验和导向全变分模型对非天空区域的透射率进行估计,从而基于大气散射模型获得去雾处理后的图像;使用一种邻域自适应的Retinex方法克服了去雾处理后图像偏暗的问题。对比实验证明,所提方法相比现有的类似方法具备更好的有效性及鲁棒性。     

含有大片天空区域图像的去雾算法

为提高包含天空区域图像的去雾效果,解决暗原色先验原理去雾容易导致天空区域色彩失真以及图像整体亮度较暗的问题,针对含有大片天空的图像,提出一种基于天空分割和色调映射的图像去雾算法.在HSI颜色空间中利用图像众数和图像连通区域提出天空识别算法,分割出天空与非天空区域;然后根据暗原色先验原理分别求取二者透射率,并在天空区域完成大气光值的估计;最后在RGB空间中利用大气散射模型复原图像,并经过改进的自适应色调映射得到最终的去雾图像.采用合成雾图、实景雾图和网络收集雾图进行实验的结果表明,该算法在主观视觉和客观指标方面均能得到质量更好的去雾图像.     

基于物理模型的雾霾天道路图像清晰化

雾霾天场景下,视频监控系统在道路上获得的图像一般都有严重降质,因此需要对图像进行去雾处理.鉴于现有的基于物理模型的方法需要很多辅助信息,提出一种新的基于物理模型的图像复原方法.该方法首先对大气散射模型进行改进,减少未知参数至一个,然后通过Hough变换求取图像的消失点,最后利用最大熵方法求取参数最优值,从而自动地对退化图像进行去雾.实验结果证明,该方法是有效和实用的.     

改进多尺度卷积神经网络的单幅图像去雾方法

针对当前已有的去雾方法容易造成天空区域存在光晕以及色彩失真的现象，提出了一种多尺度卷积结合大气散射模型的单幅图像去雾算法。将原始有雾图像与三个不同尺度的卷积核进行卷积，经过一系列特征学习后得到粗略的传播图，然后使用引导滤波器对其进行优化，得到精细化后的传播图。利用粗传播图和有雾图像计算出全局大气光。根据大气散射模型反推出无雾清晰图像。实验结果表明，该方法对天空区域的处理更加自然，在图像的纹理细节以及颜色失真上有较好的效果。     

基于物理模型的快速单幅图像去雾方法

在雾、霾等天气条件下,大气粒子的散射作用导致捕获的图像严重降质.本文提出一种新的基于物理模型的快速单幅图像去雾算法.该算法从大气散射模型出发,通过对大气光照进行白平衡,从而简化大气散射模型;利用快速双边滤波方法估计大气耗散函数,进而恢复场景反照率.本文算法的时间复杂度达到图像像素数的线性函数,具有很快的执行速度.实验结...     

结合天空识别和暗通道原理的图像去雾

目的 目前较为流行的去雾算法对天空区域的处理效果不佳,容易造成方块效应以及色彩严重失真.针对该问题,提出一种基于天空识别和暗通道原理的单幅图像去雾方法.方法 天空识别算法,将雾图分为天空与非天空部分,对其分别估计透射率图,通过大气散射模型得到复原图像;针对利用暗通道原理得到的去雾图像普遍偏暗的问题,对其进行色彩重映射,以增加图像亮度,提升图像视觉效果.结果 大量实验结果表明,本文算法复原的图像清晰自然,尤其是天空区域平滑明亮,取得了很好的去雾效果.结论 基于天空识别,提出了一种新颖的单幅图像去雾算法.与He Kaiming以及Tarel的算法相比,去雾后图像整体效果更佳.     

一种结合双区域滤波和图像融合的单幅图像去雾算法

基于大气散射物理模型和暗原色先验原理,提出一种结合 双区域滤波和图像融合的单幅图像去雾算法.首先在计算暗通道函数时,定义了一类暗区 域对图像边缘的低强度像素点进行描述,该区域像素点的暗原色中值取其三原色通道的最小值,以代替原来的中值滤波运算值.此滤波方法不仅能有效去除Halo效应,而且避免了黑斑效应;然后基 于大气散射物理模型定义一种伪去雾图,将其与原去雾图进行像素级融合对原图进行色度校正,实 现了柔性去雾,改善了现有方法易出现过去雾的缺陷.实验结果表明,该算法去雾后图像具有较好清 晰度及色彩恢复度,去雾鲁棒性强.在大雾和图像色彩失真严重的情况下,仍可有效恢复图像.     

基于暗通道先验和Retinex理论的快速单幅图像去雾方法

针对雾霾天气下捕获的图像存在低对比度、低饱和度和色调偏移等现象, 提出了一种基于暗通道先验和Retinex理论的快速单幅图像去雾方法.该方法从大气散射模型出发, 利用暗通道先验法则,通过灰度开运算对大气光值进行区间估计,同时获得介质传输率的初始估计, 并通过白平衡简化大气散射模型; 其次,基于Retinex理论,利用高斯滤波获得介质传输率的粗略估计, 并通过线性映射实现灰度值搬移; 然后,将介质传输率的初始估计和粗略估计进行像素级融合, 利用快速联合双边滤波进行边缘优化,同时通过参数自适应调整的方法对雾图中大片天空区域的介质传输 率进行修正; 最后,通过简化大气散射模型和色调调整得到复原图像.与几种典型的图像去雾算法相比, 本文算法具有很快的运算速度,能有效提高复原图像的清晰度和对比度,同时获得较好的图像颜色.     

野外视频监控图像去雾算法研究

在野外雾天环境下,由于大气粒子的散射作用导致图像降质严重,直接影响图像的视觉效果和应用价值,因此有必要对雾天图像进行去雾处理,以提高雾天图像的清晰度和保真度。为此,提出一种野外视频监控图像去雾新方法。基于暗原色先验去雾的原理,采用区域生长算法准确快速估计雾天图像的深度信息,应用雾天图像物理模型对图像去雾处理,并进行亮度补偿。实验结果表明,该算法能有效改善雾天图像的质量,大幅提高运算速度。     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

Call for Papers The 6^th International Conference on Grid and Cooperative Computing

Recent years have seen rapid advances in various grid-related technologies, middleware, and applications. The GCC conference has become one of the largest scientific events worldwide in grid and cooperative computing. The 6th international conference on grid and cooperative computing (GCC2007) Sponsored by China Computer Federation (CCF),Institute of Computing Technology, Chinese Academy of Sciences (ICT) and Xinjiang University ,and in Cooperation with IEEE Computer Soceity ,is to be held from August 16 to 18, 2007 in Urumchi, Xinjiang, China.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.     

The Distributed Time-Triggered Simulation Scheme: Core Principles and Supporting Execution Engine

Distributed real-time simulation is a young technology field but its practice is under increasing demands. In recent years the author and his collaborators have been establishing a new approach called the distributed time-triggered simulation (DTS) scheme which is conceptually simple and easy to use but widely applicable. The concept was initiated in the course of developing a new-generation object-oriented real-time programming scheme called the time-triggered message-triggered object (TMO) programming scheme. Some fundamental issues inherent in distributed real-time simulation that were learned during recent experimental studies are discussed along with some approaches for resolving the issues. An execution engine developed to support both the TMOs engaged in control computation and the TMOs engaged in DTS is also discussed along with its possible extensions that will enable significantly larger-scale DTSs.     

Software-Konfigurationsmanagement in großen Softwareprojekten

Zusammenfassung Mit zunehmender Größe der Softwaresysteme verschärfen sich die für die Software-Herstellung typischen Probleme: Beherrschen großer Objektmengen, Erhalten der Systemkonsistenz, Kontrolle der ständigen Änderungseinflüsse und Gewährleisten einer langen Lebensdauer. Die Disziplin Konfigurationsmanagement bildet den methodischen Ansatz, diese Probleme besser zu beherrschen. Software-Konfigurationsmanagement faßt die Herstellung von Softwaresystemen als eine Abfolge von kontrollierten Änderungen an gesicherten Zwischen- und Endergebnissen auf. Dargestellt werden die Objekte und Funktionen des Software-Konfigurationsmanagements sowie die hierfür in großen Software-Projekten benötigten Methoden, Instanzen und Hilfsmittel.     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and     

Editorial:Brain-machine interface(BMI) and cyborg intelligence

正Brain-machine interfaces(BMIs)aim at building a direct communication pathway between the brain and an external device,and represent an area of research where significant progress has been made during the past decade.Based on BMIs,mind information can be read out by neural signals to control     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate     

SCIENCE CHINA Information Sciences SUBJECT INDEX TO VOLUME 57(2014)

正~~