自适应复杂环境的投影图像校正算法

为实现投影仪在任意表面上的自适应投影,提出一种可以在日常环境光照条件下进行自动几何校正和色彩补偿的投影图像校正算法.该算法使用基于二进制编码结构光的离散映射集合方法,通过计算对应像素映射关系消除投影图像的几何畸变;然后应用一种优化的朗伯特反射模型构造投影表面的纹理空间,对原始投影图像进行预处理和全局亮度补偿,最终实现投影图像的颜色补偿.实验结果表明,基于文中算法在复杂环境中进行投影,可以在不规则几何表面上投影出符合视觉期望的无变形图像,并能够有效地消除投影表面固有纹理和环境光照对投影图像的干扰;将自适应复杂环境的投影图像校正算法应用于传统投影机摆脱了投影机对投影幕布的依赖,可以在任意环境中实现近似于白色平板幕布的投影效果.     

内投式球幕投影系统的实现算法

针对内投式球幕投影中涉及的计算机处理过程,提出了基于虚拟球面变换和虚拟鱼眼透镜投射的内投式球幕投影算法,并针对不规则鱼眼透镜导致的球幕映像扭曲,提出了基于等立体角投影函数的六阶函数校正算法,该六阶函数的系数可通过简单求解六元一次方程获得。实验结果表明,该方法能完全消除不规则鱼眼透镜导致的球幕投影扭曲。针对球幕投影导致的图像亮度分布变异提出了基于投射角余弦修正的球幕光强校正算法。实验结果表明,该算法成功地把与输入二维图像亮度分布差异明显的球幕投影图像校正至与原始图像亮度分布高度一致的状态。该方法对球幕投影系统的设计和软件开发具有重要的理论指导意义和实践应用价值。     

内投式球幕投影系统的实现算法

针对内投式球幕投影中涉及的计算机处理过程,提出了基于虚拟球面变换和虚拟鱼眼透镜投射的内投式球幕投影算法,并针对不规则鱼眼透镜导致的球幕映像扭曲,提出了基于等立体角投影函数的六阶函数校正算法,该六阶函数的系数可通过简单求解六元一次方程获得。实验结果表明,该方法能完全消除不规则鱼眼透镜导致的球幕投影扭曲。针对球幕投影导致的图像亮度分布变异提出了基于投射角余弦修正的球幕光强校正算法。实验结果表明,该算法成功地把与输入二维图像亮度分布差异明显的球幕投影图像校正至与原始图像亮度分布高度一致的状态。该方法对球幕投影系统的设计和软件开发具有重要的理论指导意义和实践应用价值。     

面向球幕投影系统的几何校正方法

摘 要：用于飞行模拟的视景仿真系统，经常会以多台投影仪同步投影以得到较大范围的 视场角。当投影机斜对屏幕或者投影屏幕为曲面时，图像会发生几何失真。针对此问题，本文 提出了一种专门面向球幕投影系统的几何校正方法，并以一个三通道显示系统为实例，详述了 该方法的理论原理以及校正流程。实例结果表明，经几何校正后，各投影图像无几何畸变，通 道过渡处几何内容完全一致。该方法是一种纯软件方法，成本小而且操作简单，能够适应于不 同的投影场景。     

一种抑制封闭式多投影仪显示系统的光干扰方法

360°全封闭式多投影显示系统中,为了减少各投影画面出现光线多次漫反射相互干扰,采用基于数字图像处理技术的校正方法对帧缓存的图像进行预处理,通过分析光干扰前后投影图像像素值的变化,建立帧缓存图像、光干扰前投影图像、光干扰后投影图像这三者之间的模型关系,得出预处理校正方案。经过实验证明,该技术对由封闭式多投影显示系统光干扰造成的图像对比度降低是可行的,且得到了很好的效果。     

多通道视景仿真投影系统交互式几何校正技术

为了简洁高效地解决多通道视景仿真系统投影图像的几何校正问题,提高几何校正精度,提出一种针对曲面屏幕的交互式几何校正技术.利用曲面屏幕的深度特性,以十分便捷的交互方法对现场每台投影机进行直接线性定标,再结合视景仿真系统相应通道的视锥信息自动计算该通道投影图像的几何校正网格.在系统定标中不需要辅助相机,只利用显示对象作为定标参照物,使估算的投影机模型参数更为优化,同时大大降低了系统安装调试的复杂度,提高了投影图像几何校正的效率和精度.实例结果表明,文中方法在实际应用中取得了良好效果,其计算结果还可为电子或光学边缘融合提供形状因子.     

多投影仪显示系统的几何失真校正方法

为了解决在直接获取投影墙与摄像机间几何关系较困难情况下的系统的几何失真问题,提出了基于矩阵分解和消除投影墙坐标系的自由度来获取校正参数的方法。通过系列矩阵分解和推理,得出了影响投影墙与摄像机间的几何关系的因素。在此基础上,通过消除投影墙坐标系的自由度,从2个投影仪与摄像机的几何关系求出了投影墙与摄像机间的几何关系的多个可能解,同时通过筛选算法从多个可能解中筛选出最优解,从而最终得到投影仪与投影墙间的几何关系。最后利用该几何关系对帧缓存中图像进行预扭曲以实现几何失真的校正。实验结果表明,该方法具有较好的校正效果。     

一种投影仪相机系统几何配准的鲁棒算法

目前投影屏的反射及几何特性决定了投影仪投影图像的显示效果。为解除投影仪对标准屏幕的依赖性,借助数码相机可构成反馈系统对显示表面的缺陷进行辐射度补偿和图像校正,而其前提即是建立投影图像面与相机图像面像素之间的配准关系。为实现这一目的提出了一种能实现投影仪相机系统几何配准方法的鲁棒算法。通过设计黑白二色编码图像、显示采集编码图像的方式并对捕获图像进行二值化以及形态学处理以定位和识别采样色块,建立几何配准函数关系。该算法在平面、曲面以及无图案与有图案等各种显示表面的投影场景中得以验证,其平均配准误差稳定在0.2～1.0个像素单位,且不依赖于色块的数量而变化,并能在10s内完成整个配准关系的建立。实验表明该方法能在适用范围以及精度和效率等方面满足相机反馈式投影仪像面配准的应用需求。     

半球幕几何校正与标定方法的研究

为解决半球幕投影图像画面图形畸变的问题,提出一种半球幕几何校正和相机标定的方法.该方法通过3D半球幕空间与2D投影机空间的对应关系,建立投影空间数学模型.将半球幕上标定的理想球形网格反投影到投影机空间获取预变形网格.通过奇异值分解法进行预变形网格与平面透视网格间的几何关系变换,通过控制点拟合法进行相机标定,实现基于半球...     

一种锥束CT中平板探测器输出图像校正方法

为了消除平板探测器缺陷在锥束CT重建切片中引起的伪影,提出一种投影图像校正方法.通过对投影图像进行暗场和增益不一致校正,推导了像元增益系数公式;对增益系数以及像元输出的期望和方差进行直方图分析以识别坏像素,根据坏像素分布特征设计相应的插补方案;通过局部屏蔽区域数据统计暗场波动幅度并逐行修正.实验结果表明,该方法使投影图像灰度分布均匀,像元输出波动和切片伪影得到有效抑制.     

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。