利用反向投影的flash场景自适应视频编码算法

针对闪光造成的光照变化会导致视频帧之间巨大的强度差异问题,提出利用反向投影的flash场景自适应视频编码算法;根据直方图差异提取闪光和非闪光帧,相应地为每个帧分配适当的编码类型,并在加权预测(WP)参数集确定中采用运动向量导数,通过反向投影保证flash场景的全局一致性;实验结果显示,提出的算法在Lena、Peppers、Building、Baboon、Nestling 5个视频上的峰值信噪比(PSNR)值分别可高达32.31 dB、34.14 dB、34.76 dB、34.94 dB、35.05 dB,非常接近原始图像的PSNR;相比其他几种加权预测算法,提出的算法在PSNR及计算复杂度方面均获得了更加优越的编码性能。     

一种基于场景区分算法的背景抽取方法

视频监控面对的场景具有静态的成分和缓变的成分.为了从视频流中稳定地抽取较精确的背景,提出了一种基于场景区分的背景抽取算法.首先通过混合高斯模型对视频序列中稳定的成分进行建模,然后采用Kalman滤波模型对视频序列中变化的成分进行建模,最后采用场景的区分算法将2种模型结果进行处理从而得到背景.实验结果表明:该方法能从视频...     

带电作业绝缘斗臂车虚拟仿真系统的设计与开发

将带电作业中的绝缘斗臂车操作训练与虚拟现实技术相结合,以Quest3D4.0和VC++ 6.0等软件为开发平台,在完成整体设计的基础上实现了绝缘斗臂车虚拟仿真系统。系统通过建立视景仿真和绝缘斗臂车模拟控制系统,受训者可在虚拟操作环境中真实体验在现实世界中的工况,有力地保障了仿真培训的效果,为电力系统的带电作业培训提供了一种新的思维方式。     

中医按摩机器人研制与开发

针对中老年人退行性疾病和慢性疾病对中医按摩及保健康复设备的临床需求,提出了一种中医按摩机器人系统,并对按摩机器人的机械结构、控制系统及各功能模块进行了介绍.利用传感器信息融合技术、人机交互技术、三维仿真技术等,实现了典型中医按摩手法的建模,提出了串并联结构融合的机器人构型,研制了集多种按摩手法于一体的多功能按摩机械手....     

混合视觉系统中共同视场的确定与3维重建方法

利用一个单目摄像机和一个全景摄像机搭建了相应的混合视觉系统,通过分析两者的对极几何关系,提出该系统共同视场的确定方法.在此基础上完成共同视场中场景SIFT特征的提取,并以SIFT描述器向量之间的夹角为约束条件进行特征点间的初次匹配,然后利用外极线约束消除初次匹配中的误匹配,从而获得正确的特征匹配关系,由此完成局部场景的...     

Multi-Modal Dialog Scene Detection Using Hidden Markov Models for Content-Based Multimedia Indexing

A class of audio-visual data (fiction entertainment: movies, TV series) is segmented into scenes, which contain dialogs, using a novel hidden Markov model-based (HMM) method. Each shot is classified using both audio track (via classification of speech, silence and music) and visual content (face and location information). The result of this shot-based classification is an audio-visual token to be used by the HMM state diagram to achieve scene analysis. After simulations with circular and left-to-right HMM topologies, it is observed that both are performing very good with multi-modal inputs. Moreover, for circular topology, the comparisons between different training and observation sets show that audio and face information together gives the most consistent results among different observation sets.     

Zodiac: A history-based interactive video authoring system

Easy-to-use audio/video authoring tools play a crucial role in moving multimedia software from research curiosity to mainstream applications. However, research in multimedia authoring systems has rarely been documented in the literature. This paper describes the design and implementation of an interactive video authoring system called Zodiac, which employs an innovative edit history abstraction to support several unique editing features not found in existing commercial and research video editing systems. Zodiac provides users a conceptually clean and semantically powerful branching history model of edit operations to organize the authoring process, and to navigate among versions of authored documents. In addition, by analyzing the edit history, Zodiac is able to reliably detect a composed video stream's shot and scene boundaries, which facilitates interactive video browsing. Zodiac also features a video object annotation capability that allows users to associate annotations to moving objects in a video sequence. The annotations themselves could be text, image, audio, or video. Zodiac is built on top of MMFS, a file system specifically designed for interactive multimedia development environments, and implements an internal buffer manager that supports transparent lossless compression/decompression. Shot/scene detection, video object annotation, and buffer management all exploit the edit history information for performance optimization.     

基于VEGA PRIME的无人机飞行视景仿真系统的研究

介绍了计算机仿真技术在无人机飞行仿真中的应用,讨论了系统实现的关键技术。利用三维几何模型,动态显示,3D地形LOD算法等技术,并结合C＋＋编程语言构建了一个基于MultiGen Creator／Vega软件的无人机飞行视景仿真系统,得到了满足系统的实时性及真实感的渲染效果。     

VRML虚拟场景跳转实现

基于VRML(Virtual Reality Modeling Language)构造复杂三维场景时,通常需要多个场景的组合和链接。如何实现三维场景空间的流畅跳转则十分关键。本文结合实例介绍了利用Anchor组节点实现虚拟场景间跳转的方法,从而有效服务于网络中复杂三维虚拟场景空间的跳转。     

基于OGRE引擎的森林场景渲染研究

森林场景的实时渲染仍然是图形学领域的一大难题。针对森林场景的复杂性和大数据量等特点,该文在OGRE图形引擎的基础上,通过八叉树结合OGRE中的静态几何体的方法实现大规模森林场景的实时渲染。实验结果表明通过这种方法能够在实时渲染的基础上仍能保持较好的视觉效果。