文本驱动下的表情合成系统

阐述了一种通过文本来实时驱动表情合成的系统的工作原理：在给表情进行基本分类后,将这些分类与具有感情色彩的词形成对应关系。然后在对句子的切词过程中找到这些词,并判断它们在句子中的性质,由一定的修饰关系和主谓关系讨论它们对虐拟人物的表情的影响。最后利用表惰与肌肉运动的对应关系,驱动虚拟人物面部表情,呈现给使用者。该文希望通过对文本驱动表情技术的研究,完善交互系统和虚拟系统,解决虚拟人物表情实时合成问题,并降低虚拟人物的制作费用,提高制作效率。     

文本驱动的面部表情合成系统的设计与实现

本文设计并实现了文本驱动的面部表情合成系统。本系统可以应用于聋哑人辅助教学。     

一个聋哑人辅助教学系统

为促进聋哑人与正常人之间的交流，本文设计并实现了一个聋哑人辅助教学系统．该系统的功能是能够在文本的驱动下实时合成一个有表情，有口型，有手势动作的三维虚拟“图形人”．对于用户任意输入的一段文本，系统首先将其切分成词的序列，然后顺次驱动“图形人”根据当前词蕴涵的感情色彩做出相应的表情，同时作出该词发音时的相应口型并打出对应于当前词的哑语手势．本系统可以直接应用于聋哑人辅助教学．     

基于文本驱动的人脸表情动画系统

人脸表情动画是计算机图形学的重要研究领域之一,在影视和游戏中的虚拟人的应用促进了它的发展,它主要研究若干种典型表情的产生以及利用已有表情产生中间过渡表情。本文主要介绍了表情动画的研究现状,并且设计实现了基于文本驱动的人脸表情变化系统。     

基于唇动特征的语音端点检测

针对强噪声环境下语音端点检测问题,本文提出了一种利用唇动特征检测语音端点的新方法.首先进行人脸和嘴唇检测,然后分别用PCA法或DCT法对嘴部特征进行提取,再用概率神经网络进行唇动分类和识别.实验表明,在强噪声的环境下利用视觉通道的唇动特征进行语音端点检测是可行的.     

基于内唇特征提取的唇语识别

将现有唇读识别常用的双唇线口型模板简化优化,创建了单唇线即内唇口型模板,并结合内唇的灰度特征,利用相关函数的相似性匹配实现唇语识别.该方法在准确有效提取特征的同时降低了运算复杂度,实验数据为单纯的视觉信息,集合为单个发音时,识别率可达90%.实验证明新的尝试具可行性.     

基于IOHMM的语音驱动唇动合成系统

针对语音驱动的唇动合成系统进行基于小波包分析的语音特征提取,采用特征差分和口形帧前后关联的多帧语音表征语音的动态特性,利用主成分分析降低输入语音的特征维数。采用基于输入输出隐马尔可夫模型（IOHMM）的音视频映射模型构建语音驱动唇动合成系统,实验表明提取的语音参数比传统Mel倒谱系数鲁棒性更好,合成的口形序列更连贯、自然。     

文本驱动的聋哑人手语合成系统

主要介绍作者在文本驱支的聋哑人手语合成研究领域取得的研究成果,给出了手语、手势的形式化定义,介绍了设计、实现的文本驱动的聋哑人手语合成的结构和手语合成过程,提出了虚拟三维人手及手臂的抽象结构、手及手臂的运动控制模型、手语参数的获取方法,手势库的建立方法以及手及手臂的运动控制算法;给出了详细的实验结果及结论。     

基于唇动的说话人识别技术

针对说话人识别技术多基于语音的现状,文章提出了一种新颖的基于唇动的说话人识别技术。通过离散余弦变换,从说话人讲话时的图像序列提取那些既反映说话人嘴部生理特性也反映了说话人唇动的行为特性的视觉特征。基于这些特征,为说话人建立静态-动态混合模型,其中使用半连续隐马尔可夫模型为说话人建立动态模型。在一个小型的视觉语料库上,我们分别对说话人辨认系统和确认系统进行实现。对说话人辨认系统,其文本有关与文本无关模式的正确率分别达到了100%和99.7%;对说话人确认系统,文本有关与文本无关模式的等错误率分别为0.09%与0.33%。     

基于参数化运动合成的运动图构建及其应用

虚拟人运动的可控性和逼真性是虚拟现实应用中追求的重要目标,为了实现对虚拟人的灵活控制,合成出逼真的运动序列,提出了基于参数化运动合成的运动图方法.运动图的结点中存储了具有明确含义的控制参数,通过改变控制参数合成不同的运动片段,可以实现对虚拟人的灵活控制;提出了一种改进的运动融合方法,运动图的边将不同运动片段进行融合,有效的避免了脚步滑动和根关节朝向抖动的产生.根据用户对交互控制和路径轨迹的不同应用需求设计实验,实验结果表明,方法不仅具有较高的控制精度,而且合成的运动序列逼真自然.     

Representation Analysis and Synthesis of Lip Images Using Dimensionality Reduction

Understanding facial expressions in image sequences is an easy task for humans. Some of us are capable of lipreading by interpreting the motion of the mouth. Automatic lipreading by a computer is a challenging task, with so far limited success. The inverse problem of synthesizing real looking lip movements is also highly non-trivial. Today, the technology to automatically generate an image series that imitates natural postures is far from perfect. We introduce a new framework for facial image representation, analysis and synthesis, in which we focus just on the lower half of the face, specifically the mouth. It includes interpretation and classification of facial expressions and visual speech recognition, as well as a synthesis procedure of facial expressions that yields natural looking mouth movements. Our image analysis and synthesis processes are based on a parametrization of the mouth configuration set of images. These images are represented as points on a two-dimensional flat manifold that enables us to efficiently define the pronunciation of each word and thereby analyze or synthesize the motion of the lips. We present some examples of automatic lips motion synthesis and lipreading, and propose a generalization of our solution to the problem of lipreading different subjects.     

一种快速、鲁棒的唇动检测与定位方法

提出了一种利用唇色在彩色空间分布信息和唇在人脸区域的几何分布特性进行快速、鲁棒的唇动检测与定位的方法。在该方法中,首先提出采用有约束的Fisher变换进行嘴唇图像增强;然后利用嘴唇在人脸区域的几何分布特性,来提高唇动定位的速度和准确性,唇动定位主要利用两种几何分布特性：（1）利用唇的区域面积和人脸的区域面积比值变化范围不大这一特性自适应确定区分唇色和肤色的值。（2）利用外唇参数与内唇参数之间有近似线性关系的假设,用外唇参数预测内唇参数,克服内唇定位经常陷于局部最小、定位不准的缺陷。实验证明,该唇动检测与定位系统无论从速度还是从可靠性、准确性都能满足应用的要求。     

Optimal Motion Synthesis – Dynamic Modelling and Numerical Solving Aspects

A general approach for generating optimal movements of actuatedmulti-jointed systems is presented. The method is based on theimplementation of the Pontryagin Maximum Principle (PMP) used as amathematical optimization tool. It applies to mechanical systems withkinematic tree-like topology such as serial robots, walking machines,and articulated biosystems. Emphasis is put on the choice of anappropriate dynamic model of the multibody system, together with thechoice of relevant performance criteria to be minimized for generatingthe optimal motion. It is shown that the Hamiltonian formalism isperfectly suitable to deal with the optimization problem using the PMP.On the other hand, prominence is given to performance criteria ensuringsoft and efficient functioning of the articulated systems. Two computingtechniques for solving the optimization problem are presented. Threenumerical simulations demonstrate the applicability of the method.     

Smart Motion Synthesis

Creating long motion sequences is a time‐consuming task even when motion capture equipment or motion editing tools are used. In this paper, we propose a system for creating a long motion sequence by combining elementary motion clips. The user is asked to first input motions on a timeline. The system then automatically generates a continuous and natural motion. Our system employs four motion synthesis methods: motion transition, motion connection, motion adaptation, and motion composition. Based on the constraints between the feet of the animated character and the ground, and the timing of the input motions, the appropriate method is determined for each pair of overlapped or sequential motions. As the user changes the arrangement of the motion clips, the system interactively changes the output motion. Alternatively, the user can make the system execute an input motion as soon as possible so that it follows the previous motion smoothly. Using our system, users can make use of existing motion clips. Because the entire process is automatic, even novices can easily use our system. A prototype system demonstrates the effectiveness of our approach.     

基于分块主成分分析的人体运动合成

在高维运动数据处理中,传统降维方法过度关注于保护拓扑结构和重构信息,导致低维子空间参数具有不可理解性。针对该问题,提出一种基于分块主成分分析的运动合成方法。对根据人体骨骼结构特点分组的运动数据进行分块主成分分析,获得具有特定语义的低维子空间参数。以跳跃运动为例进行实验,结果表明,该方法通过直观地改变具有语义的运动参数,可实时合成满足要求的运动结果。     

基于Web的CAI系统开发与实现

文中介绍了适用于远程教学环境的《计算机网络》课件的系统设计思想及部分实现技术。该课件的特点是界面较好,方便实用,且其中的动态演示构件具有强大的人机交互功能。     

艺术体操动作辅助编排系统

针对艺术体操个人项目与集体项目编排的特点,采用运动捕获技术、运动编辑和合成技术以及音乐特征提取等技术,开发了艺术体操动作辅助编排系统.该系统可以对个人和集体动作编排的整个流程进行辅助,从而缩短动作编排时间,拓宽教练员创作空间,提高动作编排质量.     

基于分布式控制的计算机教学刷卡系统

计算机教学刷卡系统用于计算机实验室教学管理，具有很高的实用性与现实意义。本文从发展、应用、结构和效果几方面．并结合实际使用叙述了该系统的基本特点。     

State of the Art in Example-Based Motion Synthesis for Virtual Characters in Interactive Applications

Animated virtual human characters are a common feature in interactive graphical applications, such as computer and video games, online virtual worlds and simulations. Due to dynamic nature of such applications, character animation must be responsive and controllable in addition to looking as realistic and natural as possible. Though procedural and physics-based animation provide a great amount of control over motion, they still look too unnatural to be of use in all but a few specific scenarios, which is why interactive applications nowadays still rely mainly on recorded and hand-crafted motion clips. The challenge faced by animation system designers is to dynamically synthesize new, controllable motion by concatenating short motion segments into sequences of different actions or by parametrically blending clips that correspond to different variants of the same logical action. In this article, we provide an overview of research in the field of example-based motion synthesis for interactive applications. We present methods for automated creation of supporting data structures for motion synthesis and describe how they can be employed at run-time to generate motion that accurately accomplishes tasks specified by the AI or human user.