一种基于压缩感知的快速图像处理算法研究

图像分形编码处理数据较多、压缩编码时间过长。论文提出了一种快速图像处理算法,对低频子图进行分形编码,以缩短图像压缩编码的时间,然后采用低频差值,对图像实施压缩感知编码来获取解码之后包含的图像内容信息。实验结果表明本文算法可以提高图像分形编码速度,改进重构图像的解码质量。     

分形图像压缩技术在神经网络中的实现

由于分形图像压缩技术具有解码分辨率无关性、快速编码及高压缩比和低损耗率等特点而被广泛应用,但基于迭代函数系统的分形图像编码方法却存在着计算量大的缺点,采用神经网络对分形图像进行压缩及解压缩目的在于解决压缩时间较长等问题.文中使用神经网络方法以并行方式完成对分形图像的压缩与解压缩.并通过实验,在实验中结合非线性网络和最速下降法实现对分形图像的压缩,在基本保证重建图像质量的前提下,减少了压缩时间,提高了压缩质量,进而说明神经网络技术应用于分形图像压缩中的可行性.     

基于Mandelbrot集和Logistic映射的分形图像压缩编码

改变传统的一幅图像对应一个压缩字典、一幅图像固定一张量化表的分形图像压缩方法,提出基于M集和Logistic映射的分形图像压缩编码算法.采用函数f(z)=z2 c,生成M集曲线,使用Logistic混沌映射生成的量化表量化M集曲线,生成图像块,构成丰富的压缩字典.编码时将量化后的M集图像块与压缩字典中的图像块进行匹配,选出满足条件的图像块,然后对该图像块进行编码;解码时读取压缩字典,重建图像.该算法生成了丰富的压缩字典,解码图像质量高,并且比传统分形图像压缩算法压缩比高.     

基于整数小波变换和零树编码的监控图像压缩

图像的小波变换压缩编码是近年来图像压缩领域的热点之一。本文介绍了将小波图像编码技术应用于相对图像复杂度较少的监控图像,并在PC和DSPs两个平台上分别进行了压缩编码实验,得到了比JPEG标准更好的压缩效果。     

JULIA图像与快速分形图像压缩编码

首先，本文根据统计规律建立一个小型固定字典，用以加速分形图像的压缩编码； 然后，利用逃逸方法生成Julia图像算法生成8×8的图像块，用作分形图像的压缩编码． 因此，本文使用的压缩方法改变了由通常设计的分形图像压缩编码方法以变化的压缩编码字 典进行编码的缺点．实验结果表明，本文所使用的方法能很好地对图像进行分形压缩编码， 并具有分形图像的部分解码优点．     

基于分形压缩的整数小波图像水印技术

通过对现有图像压缩和水印技术的研究,考虑图像压缩率和图像恢复的容错能力,提出了一种基于分形图像压缩编码的整数小波图像水印技术.水印嵌入时,用分形压缩编码技术对灰度水印图像进行高效压缩,再把压缩编码嵌入到载体图像的整数小波系数里,实现了在数字图像整数小波变换域中水印的大容量无损嵌入.根据提取算法,盲提取水印图像的分形编码,分形解压缩获得水印图像.经过实验验证,本水印技术具有较好的数据压缩和隐蔽性能,达到预期的设计目的.     

一种基于小波包变换的分形编码方法

利用小波包分析对高频部分进一步分解的特点,尝试将分形编码和小波包变换相结合来进行图像压缩。首先将图像进行小波包分解,然后对高频部分采用基于小波变换的压缩,对低频部分进行分形压缩。计算机模拟试验表明,采用上述改进方案,与基本分形编码相比,编码速度提高了20倍左右,且重建图像的主观保真度更高。     

基于分形集的图像压缩方法

分形图像编码是一种极具发展前途的图像压缩方法,但由于其发展时间较短,还有许多问题尚待解决,其中较为突出的是,在很长的编码时间和较高的压缩比下重构图像质量尚不能令人满意。提出了一种新颖的分形图像压缩算法,即基于Julia集的分形图像压缩方法。该算法采用Julia曲线集合作为压缩编码字典,使用自适应四叉树法实现图像压缩。通过计算机模拟实验结果显示,此算法具有较高的图像压缩比和高质量的重建图像,编码速度提高也很明显。     

基于GEP的分形图像压缩并行算法

传统图像压缩算法存在图像压缩率不高、寻找最优分形图像压缩编码速度慢的不足。为此,提出一种基于基因表达式编程(GEP)的分形图像压缩并行算法。分析二值图像压缩变换的求解过程,给出分形图像基因和染色体的编码表示,设计适应度函数,研究GEP遗传进化操作的编码步骤。在PC机群上的实验结果表明,与串行算法相比,该算法的图像压缩率较高、运行速度较快,具有线性加速比。     

低熵图像序列无损压缩

大规模的云渲染技术带来了大量的三维图形渲染数据。为了减小集群渲染产生的图像序列数据的传输以及存储代价,针对渲染图像序列低熵的特点,基于字典编码技术提出了降低数据局部复杂性的无损数据压缩方案。该方案通过数据重排技术来大大提高数据的局部冗余度,从而提高数据无损压缩效率。为了进一步解决大规模图像序列的压缩耗时问题,提出了一种云计算平台上的分布式图像压缩处理方案,充分利用现有云计算中Map/Reduce计算模型实现了分布式编码方案。实验结果证明,对于渲染产生的大规模低熵图像序列,提出的方案能够有效提高编码率并减少编码时间。     

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。     

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.     

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。     

基于AD9626的模拟信号采集存储卡设计

自然界的绝大部分信号都是以模拟的形式存在,因此模拟信号的采集转换存储在数字时代十分关键。文章讨论了在雷达信号处理领域基于AD9626的AD采集存储卡的设计原理、硬件结构和程序设计与芯片配置等问题,为今后相关领域的研究提供了可参考的方案。     

A human-computer interface for non-computer specialists

The COM teleconferencing system was designed to be easy to use for both beginners and people with much computer experience. A number of design choices in organizing the human-computer interface were considered very carefully. These design problems are not unique for teleconferencing applications, but will appear in many other developments of human-computer interfaces for non-computer specialists. This report discusses naming conventions, menu format, user commands, help facility and the treatment of ‘type ahead’ from the users.     

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.     

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.     

Call for papers Special issue on Modeling and control technologies for civil,energy,and power systems

正The control of civil,energy,and power systems presents significant new challenges for modeling and control theory.The purpose of this special issue is to provide a forum for researchers and practical engineers to discuss the recent advances in modeling and control technology development for civil,energy,and power systems.Prospective authors are invited to submit their original contributions with the focus on theory or applications of modeling,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 and promote academic exchange between Chinese and foreign scientists everywhere.