A new approach to 3D reconstruction without camera calibration

In this paper, we present a new approach for 3D scene reconstruction based on projective geometry without camera calibration. Previous works use at least six points to build two projective reference planes. Our contribution is to reduce the number of reference points to four by exploiting some geometrical shapes contained in the scene. The first implemented algorithm allows the reconstruction of a fourth point on each reference plane. The second algorithm is devoted to the 3D reconstruction. We obtained the expected good results and the proposed method is to equip a mobile robot moving in a structured environment.     

A Dynamic Motion Control Technique for Human-like Articulated Figures

This paper presents a dynamic motion control technique for human-like articulated figures in a physically based character animation system. This method controls a figure such that the figure tracks input motion specified by a user. When environmental physical input such as an external force or a collision impulse are applied to the figure, this method generates dynamically changing motion in response to the physical input. We have introduced comfort and balance control to compute the angular acceleration of the figure's joints. Our algorithm controls the several parts of a human-like articulated figure separetely through the minimum number of degrees-of-freedom. Using this approach, our algorithm simulates realistic human motions at efficient computational cost. Unlike existing dynamic simulation systems, our method assumes that input motion is already realistic, and is aimed at dynamically changing the input motion in real-time only when unexpected physical input is applied to the figure. As such, our method works efficiently in the framework of current computer games.     

Flexible Image-Based Photometric Reconstruction using Virtual Light Sources

Photometric reconstruction is the process of estimating the illumination and surface reflectance properties of an environment, given a geometric model of the scene and a set of photographs of its surfaces. For mixed-reality applications, such data is required if synthetic objects are to be correctly illuminated or if synthetic light sources are to be used to re-light the scene. Current methods of estimating such data are limited in the practical situations in which they can be applied, due to the fact that the geometric and radiometric models of the scene which are provided by the user must be complete, and that the position (and in some cases, intensity) of the light sources must also be specified a-priori. In this paper, a novel algorithm is presented which overcomes these constraints, and allows photometric data to be reconstructed in less restricted situations. This is achieved through the use of virtual light sources which mimic the effect of direct illumination from unknown luminaires, and indirect illumination reflected off unknown geometry. The intensity of these virtual light sources and the surface material properties are estimated using an iterative algorithm which attempts to match calculated radiance values to those observed in photographs. Results are presented for both synthetic and real scenes that show the quality of the reconstructed data and its use in off-line mixed-reality applications.     

Automatic Lighting Design using a Perceptual Quality Metric

Lighting has a crucial impact on the appearance of 3D objects and on the ability of an image to communicate information about a 3D scene to a human observer. This paper presents a new automatic lighting design approach for comprehensible rendering of 3D objects. Given a geometric model of a 3D object or scene, the material properties of the surfaces in the model, and the desired viewing parameters, our approach automatically determines the values of various lighting parameters by optimizing a perception-based image quality objective function. This objective function is designed to quantify the extent to which an image of a 3D scene succeeds in communicating scene information, such as the 3D shapes of the objects, fine geometric details, and the spatial relationships between the objects.
Our results demonstrate that the proposed approach is an effective lighting design tool, suitable for users without expertise or knowledge in visual perception or in lighting design.     

Fast Cloth Animation on Walking Avatars

This paper describes a fast technique for animating clothing on walking humans. It exploits a mass-spring cloth model but applies a new velocity directional modification approach to overcome its super-elasticity. The algorithm for cloth-body collision detection and response is based on image-space interference tests, unlike the existing ones that use object-space checks. The modern workstations' graphics hardware is used not only to compute the depth maps of the body but also to interpolate the body normal vectors and velocities of each vertex. As a result the approach is very fast and makes it possible to produce animation at a rate of three to four frames per second.     

用遗传算法进行串行生产线缓冲器设计

1　引言制造系统生产线的分析、设计及优化问题 ,越来越受到工程专家们的关注 .在各类制造系统中 ,串行生产线制造系统是最简单的也是应用最为普遍的 ,所以近年来关于此类问题的分析方案已有数十种 .但是 ,由于串行生产线问题的状态维数很大 ,各种分析方法都十分复杂 ,计算量大 ,而且都没能对整条生产线状态建立一个清晰的适合优化的表达 .所以 ,现在仍没有一种有效的串行生产线优化算法 .2　生产线分析现有的一些有影响的分析方案 ,有 Buzacott[1 ] ,Hong[2 ] ,Gershinwin[3,4] ,疏松桂 [5]、谭民[6] 等人的算法 ,其中 Buzacott[1 ] 首先…     

证券投资交易系统技术实现中若干问题的研究

文章给出了一个证券交易与信托投资系统的网络结构框架和技术实现方法,并针对该类系统技术实现过程中所面临的一些关键性技术问题进行了研究与探讨,给出了相应的解决方案。这些问题与解决方案对于基于Internet的证券交易系统以及信托投资管理系统也具有一定意义。     

基于数据仓库的集成质量决策支持系统的研究

论文讨论了数据仓库的基本原理,包括数据仓库的概念、功能、特点、逻辑结构和物理结构以及数据仓库系统,集成质量系统的内涵和质量决策支持系统的决策范围,提出了基于数据仓库的集成质量决策支持系统的体系结构及其开发流程和开发的关键技术。     

分布式实时应用的两个重要问题

可预测性分布式实时ＩＰＣ是分布式实时应用的两个重要问题,本文探讨了可预测性的概念,提出了分布式实时ＩＰＣ的抽象模型,并分析影响分布式实时ＩＰＣ的主要因素,为设计分布式实时应用作一定的探讨。     

基于线段与线段求交的矩形窗口裁剪算法

我们首先对线段是否完全可见进行判定 ,然后对被裁剪线段与矩形窗口四边所在的线段是否相交进行判定并求交。若交点存在则用替换法替换相应的点 ,最后连接被替换后的点得到被裁剪后的线段 ;若交点不存在则线段完全不可见 ,线段将被完全裁剪掉。