卡通风格增强现实系统

增强现实技术将计算机生成的虚拟物体叠加到真实场景中.在传统的AR系统中,虚拟物体和真实场景视觉上存在较为明显的差异,达不到虚拟物体和真实场景无缝结合的要求.本文将增强现实技术与非真实感的绘制技术有机的结合起来,减小这种视觉差异,研究并实现了卡通风格的增强现实系统.     

基于增强现实的虚拟实景空间的研究与实现

增强现实可以把计算机产生的虚拟物体或其他信息合成到用户看到的真实场景中．本文将增强现实技术与基于图像的绘制技术有机的结合起来，研究并实现了一个基于增强现实技术的虚拟实景空间系统．首先介绍了虚拟实景空间的构造，然后着重探讨了虚拟物体与实景空间的合成方法，主要解决合成中的几何一致性和光照一致性问题。     

水彩画风格实时增强现实技术

在传统的AR系统中,虚拟物体和真实场景在视觉上存在较为明显的差异,达不到虚拟物体和真实场景无缝结合的要求。将增强现实技术与NPR有机地结合起来,减小这种视觉差异,研究并实现了水彩画风格的增强现实系统。     

基于Kinect与Unity3D的增强现实应用的设计与实现

增强现实(Augmented Reality,AR)是虚拟现实技术的一个重要分支,它强调的是真实与虚拟的无缝融合。传统的增强现实应用普遍存在设备昂贵、技术繁杂等问题。利用Kinect实时获取人体彩色图像数据、深度图像数据与骨骼关节点数据的强大功能,在Unity3D中设计与实现了一个利用手势交互控制、实时抠图并自动拍照的增强现实应用。应用测试结果表明:该应用可以很好地实现手势交互控制操作,实时合成使用者和其所选择的虚拟背景图片。同时,结合AR游戏,可以让更多的人以较低的成本体验增强现实技术带来的乐趣,具有较好的现实意义与推广性。     

基于视觉的增强现实运动跟踪算法

增强现实系统不仅具有虚拟现实的特点同时具有虚实结合的新特性，为实现虚拟物体与真实物体间的完善结合，必须实时地动态跟踪摄像与真实物体间的相对位置和方向，建立观测模,墼是而通过动态三维显示技术迅速地将虚拟物体添加到真实物体之上，然而目前大多数增强现实系统的注册对象均匀静物体，运动物体的注册跟踪尚很少有人涉足。该算法通过标志点的光流场估计真实环境中运动物体的运动参数，根据透视投影原理和刚体的运动特性确定摄像机与运动物体间的相对位置和方向，实现增强现实系统的运动目标跟踪注册。该算法构架简单、实时性强，易于实现，扩展了增强现实系统的应用范围。     

增强现实综述

增强现实(augmented reality，AR)技术可以将虚拟的物体合并到现实场景中，并能支持用户与其进行交互，它已经成为虚拟现实研究中的一个重要领域，也是人机界面技术发展的一个重要方向。为了使人们对其有所了解，该文首先概略描述了这个领域的主要研究内容和进展情况，并详细介绍了增强现实中的支撑技术、开发工具和相关理论；然后针对当前AR应用的现状，分析了实现中的难点问题，并给出了与AR普及应用密切相关的一些系统框架和开发平台的描述，最后介绍了几个典型的AR应用实例。     

增强现实中的虚实注册技术研究

增强现实是把计算机产生的虚拟物体或其他信息合成到用户看到的真实世界中的一种技术 .实现虚拟信息与真实景象的正确匹配或有机结合是每个增强现实实用系统都必须完成的一项重要任务 ,且它的具体实现需依赖于计算机硬件和软件系统的相互配合及协调 .为了有效地降低增强现实应用系统中的虚实注册误差 ,在对基于位置跟踪和相机定标技术的传统虚实注册技术进行分析的基础上 ,首先研究了仿射变换技术理论在增强现实中的应用 ,并提出了在全局仿射坐标系下 ,获取像素相对深度参数的一种策略 ;然后在对 AR中的虚实注册问题进行研究分析的基础上 ,进一步讨论了图象分析技术在虚实注册问题中的应用问题 ,并提出了一种基于数值背景表达的快速虚实注册策略 ,以提高虚实注册过程中 ,场景特征点提取的精度和速度 ;最后还分别用该仿射理论进行了动态和静态的虚实注册实验 ,实验结果表明 ,该方法能有效地降低增强现实应用系统的虚实注册误差 .     

基于增强现实技术的景观规划系统

增强现实是把计算机产生的虚拟物体或其他信息合成到用户看到的真实世界中的一种技术，利用增强现实技术，设计人员能够有效地进行建筑布局的规划和设计，本文介绍了一个典型的增强现实系统-景观规划系统的实现，针对合成虚拟景物和真实场景过程中需要解决的几何一致性和光照一致性问题，采用了局部三维重建和交互的相机定标技术来实现几何一致性；对于光照一致性，则采用了光照交互指定和自动恢复相结合的方法，同时还考虑了虚拟物体投射的阴影，针对不同场景的实际应用，依据系统生成的结果合成图象，设计人员能够比较有效地完成对景观规划结果的直观评估。     

基于BIM+AR的建筑机器人交互研究

针对传统机器人仿真系统成本高、真实感差、工作量大等问题,结合建筑信息模型(BIM)与增强现实虚拟技术(AR),以幕墙安装机器人为研究对象,从建筑施工实际应用角度出发,设计了一种建筑机器人交互系统,并从机械臂仿真、虚拟现实漫游、增强现实功能、实时碰撞检测四个模块进行了详细设计。测试结果表明,所设计的基于BIM+AR建筑机器人交互系统虚拟建筑工作场景真实,用户可快速注册、登陆并操作系统,并可根据指令调节各关节角度与位置等信息,顺利进行玻璃搬运施工。当施工过程中发生碰撞时,系统快速检测并记录碰撞信息,同时通过听觉、视觉等将碰撞情况实时反馈给用户,便于提醒用户及时做出调整。系统各模块运行流畅,触控按钮功能正常,实现建筑机器人的交互,满足预期功能要求。     

AR技术在装备测试性验证试验中的应用研究

测试性验证试验是确认装备测试性的是否满足设计要求而进行的试验,对于提高装备测试性水平具有重要作用,但在验证试验中往往存在装备损坏、测试点限制以及操作人员技术要求高等问题,因此提出了一种基于增强现实(Augmented Reality,简称AR)技术的装备测试性验证试验应用研究,通过AR技术对装备进行建模仿真,将虚拟的配件与现实的装备相互匹配,使得平面知识转化为虚实结合的可视化立体知识,增强了验证试验的可视性、可达性以及可操作性,以此来引导操作人员完成测试性验证试验,提高验证试验的效率和正确性,并以某型号无人机为试验验证对象,证明了增强现实技术可以为实现装备测试性设计改进工作提供有效决策支撑。     

基于增强现实的飞行仿真技术研究

增强现实是继虚拟现实之后发展起来的一个新的研究热点,其真实和虚拟结合、实时交互和虚实定位特点,在军事、机械制造维护和医疗等方面有深入的应用。本文以飞行仿真技术为背景,分析了增强现实技术的应用和研究现状,总结了增强现实在飞行仿真上的关键技术。通过文本的研究,从需求及应用的角度阐明了增强现实技术在飞行仿真领域的关注点和重要性,从而为增强现实更深入的应用开拓思路。     

基于增强现实的飞行仿真技术研究

增强现实是继虚拟现实之后发展起来的一个新的研究热点,其真实和虚拟结合、实时交互和虚实定位特点,在军事、机械制造维护和医疗等方面有深入的应用。本文以飞行仿真技术为背景,分析了增强现实技术的应用和研究现状,总结了增强现实在飞行仿真上的关键技术。通过文本的研究,从需求及应用的角度阐明了增强现实技术在飞行仿真领域的关注点和重要性,从而为增强现实更深入的应用开拓思路。     

Handling occlusions in video‐based augmented reality using depth information

Augmented Reality (AR) composes virtual objects with real scenes in a mixed environment where human–computer interaction has more semantic meanings. To seamlessly merge virtual objects with real scenes, correct occlusion handling is a significant challenge. We present an approach to separate occluded objects in multiple layers by utilizing depth, color, and neighborhood information. Scene depth is obtained by stereo cameras and two Gaussian local kernels are used to represent color, spatial smoothness. These three cues are intelligently fused in a probability framework, where the occlusion information can be safely estimated. We apply our method to handle occlusions in video‐based AR where virtual objects are simply overlapped on real scenes. Experiment results show the approach can correctly register virtual and real objects in different depth layers, and provide a spatial‐awareness interaction environment. Copyright © 2009 John Wiley & Sons, Ltd.     

Designing and implementing interactive and realistic augmented reality experiences

In this paper, we propose an approach for supporting the design and implementation of interactive and realistic Augmented Reality (AR). Despite the advances in AR technology, most software applications still fail to support AR experiences where virtual objects appear as merged into the real setting. To alleviate this situation, we propose to combine the use of model-based AR techniques with the advantages of current game engines to develop AR scenes in which the virtual objects collide, are occluded, project shadows and, in general, are integrated into the augmented environment more realistically. To evaluate the feasibility of the proposed approach, we extended an existing game platform named GREP to enhance it with AR capacities. The realism of the AR experiences produced with the software was assessed in an event in which more than 100 people played two AR games simultaneously.

     

Augmented reality visualization: A review of civil infrastructure system applications

In Civil Infrastructure System (CIS) applications, the requirement of blending synthetic and physical objects distinguishes Augmented Reality (AR) from other visualization technologies in three aspects: (1) it reinforces the connections between people and objects, and promotes engineers’ appreciation about their working context; (2) it allows engineers to perform field tasks with the awareness of both the physical and synthetic environment; and (3) it offsets the significant cost of 3D Model Engineering by including the real world background. This paper reviews critical problems in AR and investigates technical approaches to address the fundamental challenges that prevent the technology from being usefully deployed in CIS applications, such as the alignment of virtual objects with the real environment continuously across time and space; blending of virtual entities with their real background faithfully to create a sustained illusion of co-existence; and the integration of these methods to a scalable and extensible computing AR framework that is openly accessible to the teaching and research community. The research findings have been evaluated in several challenging CIS applications where the potential of having a significant economic and social impact is high. Examples of validation test beds implemented include an AR visual excavator-utility collision avoidance system that enables workers to “see” buried utilities hidden under the ground surface, thus helping prevent accidental utility strikes; an AR post-disaster reconnaissance framework that enables building inspectors to rapidly evaluate and quantify structural damage sustained by buildings in seismic events such as earthquakes or blasts; and a tabletop collaborative AR visualization framework that allows multiple users to observe and interact with visual simulations of engineering processes.     

基于增强现实的物联网物体识别与虚拟交互

介绍增强现实的物联网物体识别与定位原理,分析基于数据手套的物联网增强现实虚拟交互方法,设计并实现一个物联网增强现实虚拟交互系统原型。实验结果表明,该系统能为物联网用户提供更自然的物体信息获取方式与虚拟交互体验,满足物联网相关应用对于实时性、精确度和稳定性的要求。     

Harmonic rendering for visual coherence on mobile outdoor AR environment

Rapid developments in augmented reality (AR) and related technologies have led to increasing interest in immersive content. AR environments are created by combining virtual 3D models with a real-world video background. It is important to merge these two worlds seamlessly if users are to enjoy AR applications, but, all too often, the illumination and shading of virtual objects is not consider the real world lighting condition or does not match that of nearby real objects. In addition, visual artifacts produced when blending real and virtual objects further limit realism. In this paper, we propose a harmonic rendering technique that minimizes the visual discrepancy between the real and virtual environments to maintain visual coherence in outdoor AR. To do this, we introduce a method of estimating and approximating the Sun’s position and the sunlight direction to estimate the real sunlight intensity, as this is the most significant illumination source in outdoor AR and it provides a more realistic lighting environment for such content, reducing the mismatch between real and virtual objects.

     

Exploring legibility of augmented reality X-ray

Virtual objects can be visualized inside real objects using augmented reality (AR). This visualization is called AR X-ray because it gives the impression of seeing through the real object. In standard AR, virtual information is overlaid on top of the real world. To position a virtual object inside an object, AR X-ray requires partially occluding the virtual object with visually important regions of the real object. In effect, the virtual object becomes less legible compared to when it is completely unoccluded. Legibility is an important consideration for various applications of AR X-ray. In this research, we explored legibility in two implementations of AR X-ray, namely, edge-based and saliency-based. In our first experiment, we explored on the tolerable amounts of occlusion to comfortably distinguish small virtual objects. In our second experiment, we compared edge-based and saliency-based AR X-ray methods when visualizing virtual objects inside various real objects. Moreover, we benchmarked the legibility of these two methods against alpha blending. From our experiments, we observed that users have varied preferences for proper amounts of occlusion cues for both methods. The partial occlusions generated by the edge-based and saliency-based methods need to be adjusted depending on the lighting condition and the texture complexity of the occluding object. In most cases, users identify objects faster with saliency-based AR X-ray than with edge-based AR X-ray. Insights from this research can be directly applied to the development of AR X-ray applications.     

基于增强现实的机器人远程控制系统研究

虚拟现实技术的应用使远程控制系统得到发展,增强现实技术是虚拟现实技术的拓展,它将计算机生成的虚拟物体叠加到用户感知的真实世界中.提出并实现了一种基于增强现实的机器人远程控制系统,并就其结构和关键技术进行详细的说明,实验及运行结果表明该系统能有效地改善人机交互能力,并能提高远程控制的精度.