Clinical Value of Stereoscopic Three-dimensional Echocardiography in Assessment of Atrial Septal Defects: Feasibility and Efficiency

Stereoscopic three-dimensional echocardiography（S-3DE） is a novel displaying technol-ogy based on real-time 3-dimensional echocardiography （RT-3DE）. Our study was to evaluate the feasibility and efficiency of S-3DE in the diagnosis of atrial septal defect （ASD） and its use in the guidance for transcatheter ASD occlusion. Twelve patients with secundum ASD underwent RT-3DE examination and 9 of the 12 were subjected to transcatheter closure of ASD. Stereoscopic vision was generated with a high-performance volume renderer with red-green stereoscopic glasses. S-3DE was compared with standard RT-3D display for the assessment of the shape, size, and the surrounding tis-sues of ASD and for the guidance of ASD occlusion. The appearance rate of coronary sinus and the mean formation time of the IVC, SVC were compared. Our results showed that S-3DE could measure the diameter of ASD accurately and there was no significant difference in the measurements between S-3DE and standard 3D display （2.89±0.73 cm vs 2.85±0.72 cm, P〉0.05; r=0.96, P〈0.05）. The appearance of coronary sinus for S-3DE was higher as compared with the standard 3D display （93.3% vs 100%）. The mean time of the IVC, SVC for S-3DE monitor was slightly shorter than that of the standard 3D display （11.0±3.8 s vs 10.3±3.6 s, P〉0.05）. The mean completion time of interven-tional procedure was shortened with S-3DE display as compared with standard 3D display （17.3±3.1 min vs 23.0±3.9 min, P〈0.05）. Stereoscopic three-dimensional echocardiography could improve the visualization of three-dimensional echocardiography, facilitate the identification of the adjacent structures, decrease the time required for interventional manipulation. It may be a feasible, safe, and efficient tool for guiding transcatheter septal occlusion or the surgical interventions.

Three-Dimensional Scenes Restore Using Digital Image

Encryption and decryption method of three-dimensional objects uses holograms computer-generated and suggests encoding stage. Information obtained amplitude and phase of a three-dimensional object using mathematically stage transforms overlap stored on a digital computer. Different three-dimensional images restore and develop the system for the expansion of the three-dimensional scenes and camera movement parameters. This article talks about these kinds of digital image processing algorithms as the reconstruction of three-dimensional model of the scene. In the present state, many such algorithms need to be improved in this paper proposing one of the options to improve the accuracy of such reconstruction.

Three-Dimensional Scene Encryption Algorithm Based on Phase Iteration Algorithm of the Angular-Spectral Domain

In order to increase the capacity of encrypted information and reduce the loss of information transmission, a three-dimensional(3 D) scene encryption algorithm based on the phase iteration of the angular spectrum domain is proposed in this paper. The algorithm, which adopts the layer-oriented method, generates the computer generated hologram by encoding the three-dimensional scene. Then the computer generated hologram is encoded into three pure phase functions by adopting the phase iterative algorithm based on angular spectrum domain,and the encryption process is completed. The three-dimensional scene encryption can improve the capacity of the information,and the three-phase iterative algorithm can guarantee the security of the encryption information. The numerical simulation results show that the algorithm proposed in this paper realized the encryption and decryption of three-dimensional scenes. At the same time, it can ensure the safety of the encrypted information and increase the capacity of the encrypted information.

Evolution of stereoscopic imaging in surgery and recent advances

In the late 1980s the first laparoscopic cholecystectomies were performed prompting a sudden rise in technological innovations as the benefits and feasibility of minimal access surgery became recognised.Monocular laparoscopes provided only two-dimensional(2D) viewing with reduced depth perception and contributed to an extended learning curve.Attention turned to producing a usable three-dimensional(3D) endoscopic view for surgeons;utilising different technologies for image capture and image projection.These evolving visual systems have been assessed in various research environments with conflicting outcomes of success and usability,and no overall consensus to their benefit.This review article aims to provide an explanation of the different types of technologies,summarise the published literature evaluating 3D vs 2D laparoscopy,to explain the conflicting outcomes,and discuss the current consensus view.

Design and Realization of Block Level Augmented Reality Three-Dimensional Map

In response to the construction needs of “Real 3D China”, the system structure, functional framework, application direction and product form of block level augmented reality three-dimensional map is designed. Those provide references and ideas for the later large-scale production of augmented reality three-dimensional map. The augmented reality three-dimensional map is produced based on skyline software. Including the map browsing, measurement and analysis and so on, the basic function of three-dimensional map is realized. The special functional module including housing management, pipeline management and so on is developed combining the need of residential quarters development, that expands the application fields of augmented reality three-dimensional map. Those lay the groundwork for the application of augmented reality three-dimensional map. .

Overview of 3D Scene Viewpoints evaluation method

The research on 3D scene viewpoints has been a frontier problem in computer graphics and virtual reality technology.In a pioneering study,it had been extensively used in virtual scene understanding,image-based modeling,and visualization computing.With the development of computer graphics and the human-computer interaction,the viewpoint evaluation becomes more significant for the comprehensive understanding of complex scenes.The high-quality viewpoints could navigate observers to the region of interest,help subjects to seek the hidden relations of hierarchical structure,and improve the efficiency of virtual exploration.These studies later contributed to research such as robot vision,dynamic scene planning,virtual driving and artificial intelligence navigation.The introduction of visual perception had The introduction of visual perception had contributed to the inspiration of viewpoints research,and the combination with machine learning made significant progress in the viewpoints selection.The viewpoints research also has been significant in the optimization of global lighting,visualization calculation,3D supervising rendering,and reconstruction of a virtual scene.Additionally,it has a huge potential in novel fields such as 3D model retrieval,virtual tactile analysis,human visual perception research,salient point calculation,ray tracing optimization,molecular visualization,and intelligent scene computing.

融合多源数据快速构建大规模实景三维建筑白模方法研究

针对传统的大规模城市级实景三维建模费用高、生产周期长、数据量大等问题,本文采用以高分辨率立体卫星影像为主,综合利用已有二维形式表达的基础地理实体、DEM、TDOM等数据构建城市级实景三维建筑白模的方法,并通过基于北京三号国际合作星立体卫星影像在哈尔滨主城区开展的建筑白模生产试验验证了该方法的有效性——可大幅度提高生产效率、降低生产成本,为支撑城市级实景三维大范围、深层次、全民化的应用赋能。

Bounding box extraction from spherical hologram of elementary object to synthesize hologram of arbitrary three-dimensional scene with occlusion consideration(Invited Paper)

A novel method to extract a bounding box that contains the three-dimensional object from its spherical hologram is proposed. The proposed method uses the windowed Fourier transform to obtain the angular distribution of the quasi-collimated beams at each position in the spherical hologram and estimates the bounding box by accumulating the quasi-collimated beams in the volume inside the spherical hologram. The estimated bounding box is then used to realize occlusion effect between the objects in the synthesis of the three-dimensional scene hologram.

基于卫星立体影像的城市三维模型快速构建试验

对城市三维模型的LOD分级进行了简单介绍,然后利用高分辨率卫星立体影像,分别采用立体测图、自动构建、建筑轮廓矢量+自动构建3种方法进行城市三维模型(LOD1.3级)快速构建试验,分析了试验结果,在此基础上给出了基于高分辨率卫星立体影像的城市三维模型(LOD1.3级)快速构建方法。

基于JMVC的立体视频场景突变检测算法

采用单视图运动矢量与立体视频中视差矢量联合判断的方法,提出一种立体视频场景突变检测算法.该算法首先直接从多视点编码码流中提取视差矢量与运动矢量,然后分别统计每帧的视差矢量与运动矢量的幅度平均值,最后将每帧的视差矢量与运动矢量的幅度平均值与对应阈值相比较,检测立体视频场景突变的情况.用该算法在压缩域直接对立体视频场景突变进行判断,不仅可以保证检测精度,还降低了计算复杂度.仿真结果证明了算法的有效性.

基于空域自然场景统计的无参考立体图像质量评价模型

针对现有的评价方法大都将图像变换到不同的坐标域问题,提出一种基于空域自然场景统计(NSS)的通用型无参考立体图像质量评价模型。在评价中为了更好地结合人类双目视觉特性,将左右图像融合成一幅独眼图;评价模型首先统计独眼图归一化亮度(CMSCN)系数分布规律,进而对独眼图提取空域自然场景统计特征;其次,统计视差图归一化亮度(DMSCN)系数的分布规律,并对用光流法得到的视差图提取同样的特征;最后,通过支持向量回归(SVR)建立立体图像特征信息与主观评价值(DMOS)之间的关系,从而预测得到图像质量的客观评价值。实验结果表明,该评价模型对立体数据测试库进行评价,其Pearson线性相关系数(PLCC)和Spearman等级相关系数(SROCC)值均在0.94以上;对于非对称立体图像库,PLCC和SROCC值分别接近0.91和0.93。该模型能够很好地预测人眼对立体图像的主观感知。

高话务室内场景WCDMA网络承载能力提升研究

多载波扩容和小区分裂是目前解决WCDMA室内热点区域容量提升的手段。随着3G网络的高速发展,用户渗透率越来越高,在现有系统内,传统室内场景扩容手段已无法满足重要会议、演唱会、体育赛事等大型聚会类高业务量网络保障需求。据此提出一种室内场景立体分层扩容方案,引入精确覆盖的Mini扇区分流话务,不但使室内场景网络承载能力大幅提升,而且较传统方案相比有效改善了网络质量。最后通过重要会议保障的数据分析验证该方案的有效性。

全景图像视频的场景分析与内容处理方法综述

近年来,随着全景内容获取和交互的软硬件技术的快速发展,全景图像视频的数量激增,如何对全景内容进行高质量地分析和处理越来越成为虚拟现实领域的研究热点。当前,全景内容分析和处理在理论和应用方面面临着巨大挑战,关于该领域的关键问题在已有文献中未见系统全面地总结和研究。为了更好地促进该领域的研究和应用推广,针对全景图像视频的场景分析与内容处理近期的主要工作进行综述。在全景场景分析方面,分析了全景图像视频的深度学习网络、深度恢复、重要性检测、目标检测的研究工作;在全景内容处理方面,分析了全景图像视频的交互式浏览、去抖和校正、内容编辑的研究工作。最后,对综述进行了总结,并展望了未来在立体视图下全景图像视频的场景分析与内容处理方面的研究趋势。

基于集成成像的虚实融合场景立体显示

提出一种利用三维重建技术与集成成像立体显示系统相融合的虚实模型融合显示技术。首先提取匹配图像特征点并根据图像特征点计算稀疏点云模型。其次采用密集点云生成技术生成密集点云模型,采用泊松重建技术获得物体计算机三维模型。最后构建虚实融合场景,并且利用集成成像虚拟采集系统获得虚实融合场景立体元图像阵列。

增强现实技术在犯罪现场立体绘图中的应用研究

犯罪现场绘图是对犯罪现场勘查后的重要记录措施,是犯罪现场重建还原的重要依据。针对复杂犯罪现场,本文提出了一种基于增强现实技术的犯罪现场立体绘图展示方法。该方法利用3D Studio Max软件进行现场模型制作,Unity3D软件和EasyAR工具对模型组合以及实现增强现实技术的使用,从而实现犯罪现场绘图的立体呈现、实时交互。应用结果表明,该方法直截、客观地展示了犯罪现场,减弱了个人主观想象对还原现场造成的影响,解决了传统平面现场绘图观察角度单一的问题,使现场的还原不再依赖观察者的空间构图能力,实现与犯罪现场实时交互,相较于传统的平面制图具有一定的优势。

From 2D to 3D GIS for CyberCity

In order to understand the 3D landscape with many h igh buildings in a city, the 2D GIS has to be extended to 3D GIS. The further de velopment of CyberCity has to include various applications of 3D scenes from the outdoor scenes to the indoor ones. In thispaper, some key techniques, such as data management method and dynamicalvisualization method for the outdoor and the indoor scenes, are discussed.The indoor scene is compared with the outdoor one. The idea of integratedrepresentation of the outdoor and the indoor scenes in CyberCity GIS is discusse d.

3D场景立体画面绘制的视觉感知驱动光照复用方法

针对用蒙特卡罗路径跟踪绘制3D场景立体画面的计算开销巨大,而3D warping根据左眼画面生成右眼画面,但无法正确地呈现镜面反射现象,且存在空洞的问题,提出3D场景立体画面绘制的视觉感知驱动光照复用方法.首先,逐像素地跟踪少量路径实现预绘制,通过获取左右眼画面的可视场景点表、显著性图和背景掩膜等辅助信息,完成左眼画面绘制;然后分别进行背景复用和3D warping复用,避免右眼画面部分像素的路径跟踪计算;最后,根据显著性图分配镜面反射区域及剩余空洞区域的路径样本数,在低采样水平下完成右眼画面绘制.在PBRT-V3通用测试场景下的实验表明,该方法能够准确地呈现镜面反射现象,提高绘制结果的视觉感知质量,与基于3Dwarping和路径跟踪的方法相比,其平均PSNR,SSIM和VSNR分别提高5.68%~22.62%,6.38%~19.36%和4.25%~34.53%.

环境感知的立体树木图像融合

图像融合技术是图像处理领域的研究热点之一,旨在实现源图像中获取的特定对象与目标背景之间的无缝融合.树木图像在三维场景中的显示效果常对三维场景的沉浸感产生影响.为了对三维树木图像构建的立体显示效果进行提升,本文提出了一种环境感知的立体树木融合方法.该方法首先采用模板匹配的方法获取树木对象多层次的视差图,并在融合时,依据树木对象融合到目标图像中的位置,调整融合后的视差图;然后,通过感知目标图像的颜色及光照调整树木对象的颜色;最后,通过深度计算对融合中出现的物体遮挡问题进行解决.融合结果表明本文方法可以很好地处理遮挡关系,并且构建出的立体树木具有多层次感,融合效果自然.

基于虚拟现实的三维动画立体空间设计

针对传统三维动画设计无法得到精准坐标数值的问题,该文提出虚拟现实技术下的三维动画设计和应用研究。计算像素点坐标值,利用数值微分画线算法,得到像素点所组成的直线段微分方程,获取最终输出值组成图像元素;使用虚拟现实技术,转换为立体表达方式,构建三维虚拟场景;根据视角差原理,采用摄像机模拟人眼成像效果,实现基于虚拟现实技术的三维动画设计。仿真实验结果表明,与传统设计方法相比,该文所提出的三维动画设计将虚拟现实技术应用到三维动画设计能有效提高精准坐标数值和弥补传统设计缺陷,使三维动画的设计与后期修改工作更加准确快捷。

MapGIS三维图象技术在林业专题图中的应用

介绍制作三维立体图的数据来源及获取,数字等高线高程赋值及栅格化,三维立体图生成及输出时的参数设置等关键环节的方法及要点,并指出在制图及图像输出时需要注意的问题.