草绘3维人体建模的模板形变方法

目的 采用草绘交互方式直接构造3维人体模型是当前人体建模研究的重要课题之一.提出一种草绘3维人体建模的模板形变方法.方法 针对输入的草图,首先,采用关节点定位方法获取草图中的人体关节点,根据人体结构学约束识别人体骨架结构,通过解析人体轮廓草图获取人体草图特征;其次,通过骨架模板和外观轮廓模板形变,将草图特征映射到3维人体模型,实现3维人体建模.结果 草图解析方法能有效提取草图特征,通过模板形变方法生成3维人体模型,并在模型上保持草图特征;能适应不同用户的绘制习惯,且生成的3维人体模型可用于人体动画设计.结论 提出一种草绘3维人体建模的模板形变方法,支持用户采用草绘方式进行3维人体模型设计,方法具有良好的用户适应性,对3维动画创作具有重要意义.     

采用草绘轮廓的3维人脸建模方法

为方便用户进行3维人脸形状设计,提出一种基于手绘轮廓的3维人脸建模方法。该方法的主要特点在于,一方面,引用姿态估计技术对人脸草图进行解析,将用户绘制的侧视人脸草图转换成对应的正视人脸草图,可支持用户选择多个视角绘制人脸;另一方面,采用多层映射机制建立人脸草图特征点与3维人脸特征点之间的一一对应关系,由对应特征点之间的形变量来控制生成3维人脸,保证草图笔画的几何形状信息能有效映射到3维模型中。实验结果表明,文中方法能快速生成形状新颖的特定人脸,可有效支持用户进行3维人脸形状的手绘建模。     

采用单笔画草绘的三维模型编辑方法

为提高三维模型的编辑交互性,提出一种采用单笔画草绘的三维模型编辑方法.该方法根据三维模型轮廓的数学特征,采用基于对象空间的三维模型轮廓提取方法,通过检测三维模型的轮廓点和暗示性轮廓点特征提取简洁清晰的三维模型内外轮廓;再根据用户的纸上绘制习惯,采用基于端点邻近性的笔画匹配方法获取三维模型中待修改的轮廓段.最后根据笔画与待修改轮廓段之间的对应关系对模型形变参数进行计算,采用拉普拉斯形变方法重建三维模型得到形变结果.实验结果表明,文中方法能有效地支持用户对三维模型内外轮廓进行单笔画编辑和修改.     

面向服装个性化定制的多视角轮廓三维人体快速重建方法

服装个性化在线定制需要围绕用户形状参数进行设计,传统的量体方法获取的用户形状参数误差高、反馈慢,亟需构建一种三维人体重建方法能够快速感知用户人体形状.针对此问题,提出了一种面向服装个性化定制的多视角轮廓三维人体快速重建方法.利用多级空洞卷积分割网络(multilevel dilated convolution semantic network,MDS-Net)提取人体轮廓图像中整体和局部特征,实现轮廓图像的语义分割;利用躯干参数提取网络(torso parameter extraction network,TPE-Net)提取多视角人体轮廓分割图的形状和姿势参数;利用主成分分析(principal component analysis,PCA)提取三维人体模型潜层空间的语义特征,并映射为由TPE-Net输出的形状和姿势参数,从而实现三维人体重建.在PyTorch环境下,采用4个数据集进行实验验证,结果表明,MDS-Net在测试集上的分割mIoU评分平均为0.881,能够实现整体分割和局部细节保留;TPE-Net在测试集上形状参数预测准确率为0.74,关节预测偏移距离与运动树中的索引呈正...     

面向座椅舒适性分析的三维人体参数化建模

应用三维坐姿人体模型可在座椅的设计阶段高效精确地进行座椅几何舒适性分析.参照二维坐姿人体模板拟定三维坐姿人体模型的结构要素,采用基于特征造型的方法构建三维人体模型.采用基于原型模型的参数化建模方法,实现对三维坐姿人体模型的参数化驱动.通过"人-椅"模型的几何匹配,自动精确提取坐姿人体模型的姿态角度,对比人体坐姿标准舒适...     

基于尺寸建立个性化人体模型的方法

近年来,人体模型定制已成为计算机图形学领域的重要研究课题之一。文中提出一种基于少量人体尺寸生成个性化人体模型的方法——分块优化法。首先,根据MPI人体扫描模型数据库获得人体外形形变参数与尺寸参数,采用线性相关分析方法实现由若干尺寸恢复完整人体尺寸集。其次,通过参数优化的线性回归方法分析各部位三维人体外形参数与二维尺寸数据之间的关系,并根据输入尺寸对人体模型进行进一步精调。实验表明,上述方法能够生成准确反映人体外形的人体模型。     

草图交互式地质建模研究

提出一种简单、快捷的草图交互式地质建模方法,旨在帮助地质学家们在地质勘测初期直观、快速地创建无数据地质概念模型.迄今,现存专业地质建模工具依赖成本较高的真实数据创建精细复杂的三维地质模型,且通常具有建模用时长、不易于学习和使用等缺陷.因此,采用直观的“纸-笔”建模隐喻,提供了一套从草图绘制到三维模型创建,再到三维模型编辑的完整建模流程,允许用户在自由定义的绘图平面上绘制描述模型地质特征的三维草图,并对其构成的连通草图网络实时地进行三维模型重建.模型重建使用分治的思想,大致分为3个步骤完成：首先利用三维草图的几何信息,即拐点,根据其拓扑连接搜寻草图网络中近似平面的能量最小圈,然后通过调和函数计算草图网络中每个圈包围区域的目标平均曲率标量及其法线方向,随后以Laplacian方程优化生成曲面片,最后将曲面片拼接成完整的三维模型.褶皱、断层地质现象可以分别通过重绘和切割操作进行建模.此外,利用层级结构树存储地质模型间的层级关系,并通过变形传递的方式对与形变物体接触的地质模型进行形变,从而保持了地质结构中多物质体相互接触的特性.相比现有基于草图的交互式建模工具,该方法融合了地质学知识,且能够更有效地使用少量草图描述地质物体的特征.基于用户体验调查,该方法具有操作简单、建模直观的特点,能够同时满足专业和非专业人士快速创建地质概念模型的需求.     

面向移动设备的三维人体重建方法

针对移动端的计算资源和存储空间有限等问题,本文提出了一种轻量级的三维人体重建方法.首先,采用DeepLabV3+网络对人体正面和侧面图像进行分割,获得人体净身轮廓.其次利用SMPL人体模型对三维人体进行参数化表示,并对SMPL模型的正面和侧面进行投影,获得二值轮廓作为数据集.然后,构建并训练一个教师网络以预测二值轮廓图的SMPL参数.之后,构建一个轻量级的学生网络,通过知识蒸馏的方式,利用教师网络来提高学生网络预测的人体参数精度.最后通过学生网络预测的SMPL人体参数生成三维人体模型.实验结果证明,本文的方法可以在消耗较少的计算资源和存储空间的情况下获得相对较高精度的三维人体.     

由正交图像造型三维个性化虚拟人体模型

基于正、侧、背面4幅正交人体图像,变形模板人体模型后得到带服饰纹理的个性化虚拟人．以截面环为基本几何元素,给出了模板人体模型的生成和变形方法,建立了截面环和三维人体骨架之间的内在关联;自动提取图像上的人体特征点,生成二维图像上的人体骨架;由三维人体骨架和二维图像上人体骨架之间的对应关系,建立截面环和人体图像之间的对应关系;从人体图像上获取截面环的形状参数,通过参数化变形截面环得到个性化的虚拟人体模型．与已有方法相比,该方法建立在基于特征的参数化框架之上,变形更容易控制,消除了三维模型和二维图像之间对应的不确定性,避免了人体变形中的自交现象,效率高、真实感效果较好．     

服装CAD中三维人体模型的参数化研究

针对三角网格曲面表示的3D人体模型缺少语义信息，提出一种3D人体模型的参数化方法：首先通过三角面片求交的采样策略得到采样点，然后使用B样条曲线构造人体轮廓线，最后由用户交互得到3D人体模型的参数化信息，建立3D人体模型的参数化模板．这样，在参数化人体模型模板的基础上，可以根据用户所输入的特定人体参数信息，动态地调整轮廓线和重建人体模型体表曲面，快速生成逼真的3D人体模型，从而满足服装CAD中根据用户身材尺寸大小定制服装的应用需求．     

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。