移动机器人实时目标跟踪系统设计与实现

针对单目视觉移动机器人目标跟踪的实时性和鲁棒性要求,提出了基于Kalman滤波器的改进Camshift算法检测和定位目标.将Kalman预测值作为目标初始位置,补偿摄像头和目标相对运动导致的目标在图像中的偏移.在系统“跟丢”后判断目标丢失的原因,根据原因自适应拓展搜索窗口作为Cam-shift算法的下一帧初始搜索窗口.为了验证改进算法的有效性,自主研制了一种应用该算法的履带式机器人实时目标跟踪系统.实验结果表明:该系统具有很好的鲁棒性和实时性.     

改进的Camshift跟踪算法研究

Camshift是使用颜色直方图作为特征的一种跟踪算法。它利用目标的颜色直方图模型得到每帧图像的颜色投影图,初始化一个搜索窗的大小和位置,并根据上一帧得到的结果自适应调整搜索窗口的位置和大小,定位出当前图像中目标的中心位置。从准确预测目标位置及缩小目标搜索范围入手对Camshift算法进行了改进。实验结果表明,改进的Camshift有效地克服了Cam-shift算法自身的缺陷,即使在图像背景复杂且不规则的情形下,仍然能有效的跟踪到目标。     

基于帧间差分和背景差分结合的Camshift目标跟踪算法

Camshift算法需要手动标定目标区域,且具有无法适应目标的高速运动、相似颜色背景和遮挡等情况的局限性。针对这些情况提出结合帧间差分法和背景差分相结合的方法对Camshift算法进行改进。首先利于帧间差分和背景差分相结合检测出运动目标区域。然后用该区域初始化跟踪目标窗口。当有相似颜色背景干扰或遮挡情况发生时,利用检测出的运动目标区域对搜索窗口进行限制。同时,使用Kalman滤波对下一帧的搜索窗口进行预测,从而使该算法适合高速运动目标的跟踪。实验表明该算法能够准确对目标窗口进行初始化,且在目标高速运动、遮挡、和相似颜色背景干扰情况下,仍能进行适时实时有效跟踪。     

基于图割理论的尺度自适应人脸跟踪算法

针对连续自适应的Mean-Shift（Camshift）算法跟踪人脸时尺度过度放缩这一问题,提出了一种基于图割的Camshift人脸跟踪算法。首先,在每一帧图像的Camshift迭代结果内建立图割区域,使用高斯肤色模型作为图割权值分割出图割区域内肤色团块;然后,计算该肤色团大小得到目标真实尺度,并比较与上一帧图像跟踪框内肤色团的尺度来判断是否需要重新跟踪目标;最后,再以该团块作为下一帧跟踪目标。实验结果表明,基于图割的Camshift人脸跟踪算法有效地克服了跟踪时其他肤色区域的干扰,能有效地反映人体快速运动中人脸真实尺度变化,同时防止Camshift算法丢失跟踪目标而陷入局部最优解,具有较好的可用性和鲁棒性。     

基于CamShift的目标跟踪算法

CamShift是一种应用颜色信息的跟踪算法,在跟踪过程中,CamShift利用目标的颜色直方图模型得到每帧图像的颜色投影图,并根据上一帧跟踪的结果自适应调整搜索窗口的位置和大小,从而得到当前图像中目标的尺寸和中心位置.在CamShift算法基础上对搜索窗口进行简单运动预测,并增加二次搜索方法,提高跟踪的稳定性.实验结果表明,在图像背景复杂且目标不规则运动的情形下,仍能有效地跟踪到目标.     

基于Camshift算法的运动目标检测

CamShift算法是一种实时的跟踪算法,它是利用目标的颜色直方图模型得到每帧图像的颜色投影图,并根据上一帧跟踪的结果自适应调整搜索窗口的位置和大小,从而得到当前图像中目标的尺寸和中心位置。本系统主要是基于CamShift的算法设计一个对运动目标跟踪检测系统,本系统既可以对室内环境的运动目标进行跟踪,也可以对视频流中的运动目标进行跟踪。     

多目标跟踪的改进Camshift/卡尔曼滤波组合算法

针对多目标跟踪中,目标瞬间丢失、目标交错或重叠时目标跟踪失败等情况,提出了一种改进Camshift（continuouslyadaptivemeanshift）算法和卡尔曼滤波组合的多目标跟踪方法．在Camshift算法中,从目标的颜色直方图模型得到每帧图像的反向投影图,根据目标的大小自适应地调整搜索窗口尺寸,并迭代计算各目标窗口的质心位置．通过自适应地扩展搜索窗口,从而解决了因目标加速度而引起的目标瞬间丢失问题．采用卡尔曼滤波实现对运动目标的位置估计,以克服多目标运动引起的交错或重叠以及噪声干扰．实验结果表明,这种组合算法能有效地改善多目标跟踪的性能,实现目标连续跟踪．     

一种徒手手势全自动跟踪的新方法

提出改进的Camshift算法跟踪手势,首先用Haar特征和单高斯肤色模型定位手掌手势,将手掌手势的外接矩形作为Camshift初始搜索窗口,从而实现全自动跟踪;用面向对象的思想将Camshfit算法封装成类,为每个手势建立一个类对象,从而实现双手手势跟踪;在跟踪过程中加入Kalman滤波算法预测手势位置,避免目标丢失问题。     

一种徒手手势全自动跟踪的新方法

提出改进的Camshift算法跟踪手势,首先用Haar特征和单高斯肤色模型定位手掌手势,将手掌手势的外接矩形作为Camshift初始搜索窗口,从而实现全自动跟踪;用面向对象的思想将Camshfit算法封装成类,为每个手势建立一个类对象,从而实现双手手势跟踪;在跟踪过程中加入Kalman滤波算法预测手势位置,避免目标丢失问题。     

基于均值漂移—连通域标记的多目标跟踪算法*

提出一种基于Mean Shift改进算法与连通域标记的多目标跟踪算法。在多目标跟踪过程中,对目标瞬间丢失、目标遮挡或重叠时目标跟踪失败等情况有较好的改进。在跟踪过程中,当目标丢失时,基于改进的Mean Shift算法能自适应调整搜索窗口尺寸和方向。通过自适应扩展搜索窗口,利用连通域标记算法搜索目标并计算其矩特征来获得跟踪目标的重心和大小信息,并将获得的位置和尺度信息作为下一帧Mean Shift算法跟踪初始坐标和尺度,统计目标区域颜色直方图作为Mean Shift算法目标模型,从而解决了因目标速度过快而引起的目标瞬间丢失问题。最后研究结果显示,这种改进的目标跟踪算法可以有效改善多目标跟踪的性能,实现目标连续跟踪。     

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。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.