基于DCT域的自适应二维数字水印系统

本文提出了一个以图像为水印的DCT域二维自适应数字水印算法。为实现水印图像的叠加 ,我们首先将其进行 8× 8分块并进行DCT变换 ,然后对每块的DCT系数进行调整 ,最后 ,取出每块的部分低频系数构成水印信号。为了实现自适应 ,首先将原始图像按 8× 8分块并利用视觉掩蔽特性对图像块进行分类 ,然后对每块进行DCT变换 ,根据块分类结果 ,水印信号以不同强度嵌入到图像块的DCT低频系数中。实验结果表明 ,该算法具有较好的鲁棒性。     

一种JPEG图像边缘检测算法

提出了一种针对JPEG压缩图像的边缘检测算法。该算法首次推导出了DCT域中8×8DCT块到2×2DCT块的直接变换矩阵,并以2×2DCT块为单位进行边缘检测。实验结果表明,与已有的方法相比,该算法简单易行,且提取出的边缘特征具有较高的分辨率。     

DCT压缩域中图像颜色布局描述符的提取

在国际标准MPEG-7所建议的一种颜色布局描述符基础上,针对JPEG压缩图像,阐述了在DCT压缩域中,从Y、Cb、Cr颜色分量图像的各个8×8子块的直流分量中直接提取颜色布局描述符,以方便于在压缩域中根据颜色的空间分布特征进行快速的图像索引和图像检索。     

基于块边缘特征直方图的图像检索

本文提出一种利用块边缘特征来进行图像检索的方法。首先对图像中每个8×8的块分别提取其决边缘特征,利用块边缘特征构建三维或四维直方图进行图像检索。所有数据在 DCT 压缩域中进行处理,从而降低了计算复杂度。实验结果表明,该方法与传统的基于 DCT 压缩域的图像检索方法相比,具有检索准确度高和检索速度快的特点。     

基于游程编码的块边缘模式图像检索算法

提出一种利用块边缘模式来进行图像检索的方法。该方法对图像中每个8×8块分别提取其块边缘模式，然后利用游程编码的原理，用块边缘模式构成图像的特征向量，以便进行基于内容的图像检索。所有数据在DCT压缩域中进行处理，不需要解压缩，从而降低了计算复杂度。实验结果表明，该算法与传统的基于DCT域的图像检索方法相比，具有更好的图像检索性能。     

基于方向编码的离散余弦变换域图像隐写算法

提出一种基于方向编码的离散余弦变换(DCT)域图像隐写算法。将秘密图像进行8×8块的离散余弦变换后,采用JPEG标准量化表进行量化,将得到的DCT系数做行程编码,间接提高嵌入容量。同时对载体图像进行8×8块的离散余弦变换,采用改进的量化表进行量化,由此提高嵌入容量和含密图像的质量。通过基于方向编码的嵌入算法将秘密信息嵌入载体图像DCT系数的中低频部分。实验结果证明,该隐写算法嵌入容量大,得到的含密图像视觉质量好,可抵抗 分析攻击。     

基于DC和AC分量的二维数字水印算法

提出一种新的二维数字水印算法,该算法先把原始图像分块DCT,再对水印图像分块DCT,取每一图像块的直流系数和前12个DCT低频交流系数,分别构成水印信号的直流分量和交流分量。利用能量比确定各个子块的直流拉伸因子和交流拉伸因子。水印信号的直、交流分量以不同的能量分别嵌入到原始图像块DCT域的DC分量和AC分量中。实验结果表明,该算法具有良好的不可见性和稳健性。     

基于DC和AC分量的二维数字水印算法

提出一种新的二维数字水印算法,该算法先把原始图像分块DCT,再对水印图像分块DCT,取每一图像块的直流系数和前 12个DCT低频交流系数,分别构成水印信号的直流分量和交流分量.利用能量比确定各个子块的直流拉伸因子和交流拉伸因子.水印信号的直、交流分量以不同的能量分别嵌入到原始图像块DCT域的DC分量和AC分量中.实验结果表明,该算法具有良好的不可见性和稳健性.     

基于分块DCT和量化的图像盲水印算法

当前基于离散余弦变换(DCT)的图像数字水印方法大多为非盲的，水印一般嵌入DCT的中低频系数中，但却把DC分量排除在外。该文提出了一个基于分块DCT和量化的图像盲水印算法，将水印根据量化策略嵌入块DCT系数的DC分量中。该算法思想简单，步骤简便、容易实现。实验结果表明，该算法对嵌入的水印具有很好的透明性，对常见攻击如重采样、颜色抖动、平滑、加噪声和JPEG压缩等具有很强的稳健性。     

面向移动设备的MPEG-2到H.264降空间分辨率转码*

针对无线网络中移动设备低码率、低分辨率的视频流要求,提出一种MPEG-2到H.264降空间分辨率转码的快速编码模式选择算法。在视频序列2∶1下采样后,利用MPEG-2解码端运动矢量的距离和方向信息决定是否将相邻8×8块合并成8×16、16×8、16×16块,若不能合并,则用解码端AC系数的组合判断是否将8×8块继续分割为8×4、4×8、4×4块,既考虑到H.264编码中的所有块大小,又避免了传统率失真选择算法的庞大计算量。实验结果显示,该方法在保证相当的视频质量情况下,平均节约87.02%的编码模式选择时间。     

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.     

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。     

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.     

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。     

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     

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.     

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.