高斯二阶差分特征算子在图像拼接中的应用

为了将同一场景中具有重叠区域序列的图像快速准确合成一幅具有宽视角、高分辨率的图像,提出了基于高斯二阶差分(D2oG)特征检测算子的SIFT算法.采用高斯二阶差分(D2oG)金字塔的过零点检测提取图像尺度不变特征点,并选用RANSAC算法对特征点匹配对进行提纯,在此基础上计算不变换矩阵H,最后,用渐进渐出平滑算法完成图像的无缝拼接.实验中分别采用所提方法和SIFT算法对具有典型变换的4种图像进行拼接与测试,结果表明:所提方法提取的匹配点数、拼接所消耗时间明显低于采用SIFT算法,同时匹配效率也高于后者.此方法降低了运算复杂度的同时,图像拼接实时性也得到提高.     

基于旋转采集Data Matrix码序列图像拼接方法

针对刀具柱面Data Matrix码图像拼接的特殊需求,已有算法拼接结果识读率低、实时性差的缺陷,提出了一种基于Data Matrix码图像特征的拼接方法.该方法基于缝隙内旋转采集的刀具柱面Data Matrix码序列图像,通过条码纵向位移校正与模块划分,完成基于模块信息的最小欧氏距离图像粗配准和归一化互相关图像精配准;为了保证条码结构正确,消除无重合区域对图像拼接的影响,根据匹配度先将序列图像融合成3部分并校正畸变;最后将这3部分按条码模块关系融合成一幅尺寸正确的图像,实现了条码定位、模块划分,以方便后续进行解码.实验结果表明,文中方法能够满足刀具柱面Data Matrix码序列图像的拼接需求,拼接结果解码正确率达到96％,拼接时间小于250 ms,并且大大提高了解码速度.     

基于SIFT特征匹配的图像无缝拼接算法

基于尺度不变(SIFT)的特征匹配思想和像素加权平滑的图像融合思想,提出了1种鲁棒、精确的图像拼接算法,从而解决尺度、视角及光照变化较大情况下图像拼接问题。SIFT特征匹配算法利用128维向量对特征点进行描述,利用最近邻法完成2幅图像特征点的匹配。对于粗匹配产生的误匹配对,应用随机抽样一致性算法(RANSAC)进行筛选,同时估计模型参数,并借鉴加权平滑算法消除拼接图像之间的缝隙,进一步提升拼接效果。实验结果表明,该算法在继承了SIFT算法鲁棒性的同时,进一步提升了拼接精度,降低了图像亮度等差异的影响,使拼接图像自然逼真。     

基于全局拼接的航拍图像拼接算法研究

研究航拍图像的拼接问题,提高图像拼接的准确度。由于当通过航拍获取的图像中部分图像相互存在重叠区域的比例不大时,造成拼接不准确。传统的区域的图像拼接算法无法将具有较小重叠区域的图像准确拼接。为了提高航拍图像拼接的准确率,提出一种全局的图像拼接算法,通过使用SIFT算法提取图像的SIFT特征点,根据位置误差最小的原则完成两幅图像的SIFT特征点匹配,最后利用整体最优化方法对拼接结果进行优化,采用全局特征点的拼接方法,可避免传统方法只利用重叠区域灰度特征而不能准确拼接低重叠度图像的问题。实验证明,改进方法利用图像的全局信息,准确地实现图像的拼接,取得了满意的结果。     

基于改进SIFT特征点匹配的图像拼接算法

基于传统SIFT方法和图像像素加权平滑融合的思想,提出了一种改进SIFT特征点的图像拼接方法;该方法首先利用Canny边缘检测算法获得图像的边缘点坐标,通过和SIFT算法关键点坐标进行对比,去除不稳定响应点;其次通过K-L变换降低算法复杂度,对得到的匹配点对,使用RANSAC算法进行提纯,计算投影变换模型参数;最后使用渐入渐出的加权融合算法平滑图像,消除图像之间的拼接缝隙;该算法的可行性和有效性通过实验结果可以得到证明。     

基于SIFT特征匹配的图像拼接算法

基于SIFT特征匹配思想 ,提出一种快速、准确的图像拼接算法.SIFT特征匹配算法是目前国内外特征点匹配研究领域的热点与难点,其匹配能力较强,可以处理两幅图像之间发生平移、旋转、仿射变换情况下的匹配问题,甚至在某种程度上对任意角度拍摄的图像也具备较为稳定的特征匹配能力.在这一匹配思想的基础上结合多分辨率样条提出一种新的图像拼接算法,它采用多分辨率样条来确定拼接区域宽度和加权函数,使图像在不同分辨率下分别拼合,这样使拼合出的图像既清晰又光滑无缝.算法在大多数情况下能自动完成,实验结果证明该方法提高了拼接速度,降低了图像亮度差异的影响,使结果图像自然逼真.     

基于特征点的全自动无缝图像拼接方法

提出了一种基于特征点的全自动无缝图像拼接方法.该方法采用对于尺度具有鲁棒性的SIFT算法进行特征点的提取与匹配,并通过引导互匹配及投票过滤的方法提高特征点的匹配精确度,使用稳健的RANSAC算法求出图像间变换矩阵H的初值并使用LM非线性迭代算法精炼H,最终使用加权平滑算法完成了图像的无缝拼接.整个处理过程完全自动地实现了对一组图像的无缝拼接,克服了传统图像拼接方法在尺度和光照变化条件下的局限性.实验结果验证了方法的有效性.     

基于ASIFT的无缝图像拼接方法

传统图像拼接方法对尺度、视差和光照变化较大的图像配准效果不佳。为此,提出一种基于仿射-尺度不变特征转换(ASIFT)算法的无缝图像拼接方法。采用能够抵抗强仿射情况的ASIFT算法检测特征点,并对特征点进行提取与匹配。利用随机抽样一致算法反复迭代,找到精确的变换矩阵初始值,根据变换矩阵进行2幅图像之间的统一坐标变换,使用加权平滑算法完成图像的无缝拼接。实验结果表明,与基于SIFT特征的拼接方法相比,该方法的图像拼接效果较好。     

基于SIFT特征的彩色图像拼接方法研究

针对传统特征提取拼接算法在复杂图像中配准过程中出现的过多误匹配,导致拼接后图像出现鬼影、模糊等问题,从而影响拼接图像的质量,提出一种改进的SIFT配准算法。在对目标图像提取SIFT特征后,利用SIFT描述子的尺度以及梯度方向信息建立最小邻域匹配剔除误匹配点,之后利用局部均方根误差(RMSE)评价映射矩阵与RANSAC算法相结合,迭代出精确变换模型。在对图像进行几何矫正后,提出一种自适应的混合线性算法对重合区域图像变换至HIS颜色空间进行图像拼接,最后得到平滑无缝的完整彩色全景拼接图像。实验结果证明,该算法在拼接复杂场景并且重合区域不多时仍有较好的准确性及稳定性。     

基于SIFT特征点的图像拼接技术研究

给出一种基于特征点的图像拼接方法,该方法采用对于尺度具有鲁棒性的SIFT算法进行特征点的提取与匹配,计算出特征匹配点后,使用RANSAC算法剔除误配,并计算出两幅图像之间的坐标变换关系矩阵H.最终使用加权平滑算法完成了图像的无缝拼接.实验证明,该算法有效提高了图像拼接的效率和准确性.     

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。