查询词典 virtual image

In order to apply virtual reality technique into medical image processing, make convenient for surgeons to access virtual and mini invasive surgery, this paper, presents a full interactive virtual endoscopy system framework, analyzing and discussing system architecture and algorithm models. We explain some key procedures in virtual endoscopy system such as definition of world coordinate, virtual camera, surface detection, normal approximation, volume rendering and surface rendering, and also some interactive control method.

在综合利用各种计算机图形、图象技术的基础上，提出了完整的交互式虚拟内窥镜系统的框架，同时对系统结构和各种模型进行了分析和讨论，还针对系统的实时性和绘制结果的逼真性要求，提出了基于 Object Cache和扩展的区域增长方法，并将其应用到医学图象处理当中，得到了较好的效果。

Material and Methods:From March,2008 to January,2009,250 patients(146 Males and 104 Females,ranged from 18 to 82 years old,mean age was 48 years old) enrolled in the First Affiliated Hospital of Kunming Medical College were performed dual energy scan(Group A,200 patients) and Neuro-DSA scan(Group B,50 patients) using DSCT.The patients were randomly divided into Group A and Group B.Regarding to the justification of scan protocol,100 patients in Group A were selected as sub-group to explore the scan protocol.The image quality Was analyzed both in four categories(4.0/60、4.5/60、4.0/70、4.5/70) of flow rate and total amount of contrast-enhanced material and in three categories(100—150HU、150—200HU、200-250HU) of CT value of left common carotid artery.The comparison of two scan approach was based on image quality,radiation does, postprocessing methods,time of scanning and subtraction and data storage amount.To validate the diagnostic capability of DE-CTA virtual unenhanced images,100 patients in Group A were undergoing head scan both in routine non-contrast program and DE-CTA virtual unenhanced program.Mean CT values,signal-to-noise ratio,image quality,sensitivity of lesion identification,and radiation does were applied to comparison.According to diagnostic results of dual energy of cerebral arterial angiography,62 patients out of 200 patients in Group A were confirmed with cerebral vessel lesions,the results were complied with DSA findings(the time between the two methods were within 1 week).

材料与方法收集2008年3月到2009年1月间在昆明医学院第一附属医院行DSCT CTA检查者250例(男性146例，女性104例，年龄范围18-82岁，平均48岁)，随机分为A、B两组，A组200例行双能量头颅CTA扫描；B组50例行Neuro-DSA扫描。A组前100例按对比剂不同流率和总量分为4组(4.0/60、4.5/60、4.0/70、4.5/70)对图像质量比较；按触发时左颈总动脉内平均CT位分3组(100—150HU、150—200HU、200-250HU)，比较图像质量的差异；对A、B两组血管图像质量、辐射剂量、后处理的方法、扫描和后处理时间及数据的容量进行比较分析；A组中前100例行常规与DE-CTA虚拟平扫的平均CT值、信号噪声比、图像质量、病灶显示情况、辐射剂量的比较分析；A组中行DSA检查62例(两种方法间隔时间均1周内)，比较两种检查方法诊断结果是否符合，并对其中24例动脉瘤行动脉瘤部位、数目、形态、瘤颈显示程度、瘤颈大小及瘤体长径和短径的比较研究。

First, an initial projection matrix is obtained through homography between an image and a scene plane. The homograph matrix between two images, i. e., the image plane and the scene plane, can then be calculated from matching points of these two images. Thus the projection matrix of every next frame can be calculated from homograph matrix between the current image plane and the previous one. Registration of virtual objects is finally completed.

根据这个原理，首先通过一个景物平面和图像之间的单应得到初始状态相机的投影矩阵，然后对后面每帧图像和前一帧进行自然特徵点匹配，通过匹配点对计算出图像之间以及图像与景物平面的单应关系，由此就可以得到每一帧图像对应的相机的投影矩阵，从而完成虚拟物体的注册。

Generally, the main research points in this paper are as follows:Image Stitching is one of the key technology in virtual reality construction,we proposes two ambient light independent panorama mosaics methods based on feature: image stitching algorithm based on stationary wavelet decomposition and homomorphic filtering, and image stitching algorithm based on ring projection and energy function optimization.

主要研究内容如下：图像拼接是虚拟场景建模的主要技术之一，针对光照变化图像序列提出了两种基于特征的图像拼接算法：基于静态小波序贯特征匹配和同态滤波的图像拼接算法以及基于圆投影和能量函数优化的图像拼接算法。

Aimed at the needs of virtualized relationship in virtual environment, we introduce non-photorealistic rendering into virtual reality and presented a novel algorithm for virtualized relationship generation in image based virtual environment based on line integral convolution.

针对基于图像的虚拟场景虚化关联的需要，将非真实感绘制技术引入虚拟场景中，提出了一种基于线积分卷积的场景虚化关联生成方法。

First, structure tensor is calculated to gain vector field for characterizing local structure of image. And then, total variation partial difference equation is imposed for smoothing vector field. Based on this we use line integral convolution for guide the stroke to generate virtual special effect image with fluctuant sense. Last, mergering with original real image, cylindrical panorama with virtualized relationship controlled by time can be generated, which accomplished the character of surpass the time and space in virtual reality system.

该方法通过计算结构张量获得图像曲线走向矢量场，以此刻画图像局部结构；并采用全变分偏微分方程对曲线走向矢量场自适应滤波平滑处理；在此基础上利用线积分卷积指导画笔走向模拟生成线条波动感虚化效果图像；最后结合原始真实图像和虚化效果图像，实现了一种基于时间变量的柱面场景虚化关联算法，并为虚拟现实系统超越现实时空的需要提供了一种新思路。

On the basis of Earth surface space using reference ellipsoid as height basis, map space using Gauss-Kruger projection plane as height basis, a viewpoint is proposed that map projection actually establishes corresponding relationship between the height bases of two different spaces above. From the viewpoint of projection and visible representation, the relationships among earth surface space, RS imagery space and map space are analyzed; the differences among different representations of earth surface space are identified theoretically; virtual reality is applied to the representation of land surface space, and a prototype of real 3D virtual reality system based on spatial information is developed. By means of digital simulation, virtual reality representation of land surface space in visual image space is realized.

在以参考椭球面为高程基准面表征地表空间、以高斯-克吕格地图平面为高程基准面表征地图空间的思想基础上，提出了地图投影实质上是建立两个空间的高程基准面之间关系的观点；从投影和可视表达的角度，分析了地表空间、遥感图像空间、地图空间之间的关系，从理论上区分了对地表空间的不同表达方式之间存在的差别；将虚拟现实技术应用于地表空间的表达，研制了空间信息三维虚拟现实系统原型，利用数字模拟技术在视像空间实现了对地表空间的真三维虚拟现实表达。

A surface capable of reflecting sufficient undiffused light to form a virtual image of an object placed in front of it.

镜能够反射足够的非散射''。'性'。''光从而能形成放置于其前的物体的真实图像的一个''。'平面'。

According to the deficiency of Image Fusion applications in entertainment equipments, such as no special research that combines Virtual Reality, Self-control Photographing, Computer Vision and Image Fusion technologies together, we propose an Image Fusion algorithm base on Character of Apperceiving Contrast, which take system elements into account, e.g. integrity image quality balance and costs.

鉴于目前对图像融合技术在娱乐领域的应用缺乏研究，尤其缺乏将虚拟现实技术、自助照相技术、机器视觉技术和图像融合技术综合运用的分析研究，因此我们从分析人类视觉特征入手，运用系统的观念综合平衡图像质量、系统成本等技术指标，在对虚拟实时自助照相系统具体技术指标深入分析的基础上，提出了基于对比度感知特征（Character of Apperceiving Contrast）的图像融合算法。

According to the function of distributed emulator, optical information processing and image multi-object tracking system, the following three aspects were emphasized in this dissertation. Firstly, a vast virtual terrain, ground radar models and canyons were created for the distributed emulator with modeling software Creator. The radars were driven to scan during emulating and the real time terrain code was sent to Radar module. Secondly, an optics channel simulating the optics camera of a virtual aircraft was implemented with simulating software Vega. The 2-D information got from the channel was translated and sent to multi-sensor information fusion system as an optics information source. Thirdly, the dissertation studied some motion estimation methods and analyzed the factors which influence the speed and the precision of the block matching algorithms. Then an improved block matching method was proposed for image multi-object tracking system and applied in the system combined with frame difference method.

论文根据多传感信息融合实验系统中的分布式飞行仿真系统、光学信号处理器和图像多目标跟踪系统三个子系统的功能要求，具体完成了以下三方面的工作：首先利用建模软件Creator创建分布式飞行仿真系统中的大面积地形、场景中的地面雷达模型和峡谷地形，并在仿真过程中实时驱动雷达模型的扫描，同时为后续雷达仿真模块提供实时地形编码；其次利用仿真软件Vega，在分布式仿真系统中为光学信号处理器设计实现了光学通道，模拟飞行器的光学摄像机的功能，并且对由此通道获得的目标二维光学信息进行转化处理，作为光学信息源发送给后续的多传感信息融合器；最后针对图像多目标跟踪系统，在研究图像分割运动估计算法的基础上，通过分析影响块匹配算法速度和精度的因素，改进了块匹配运动估计算法，结合差分法可应用到目标跟踪系统中。

If you are unfortunate enough to the lovelorn, please tell me, I will help you out, really, please contact me!

如果你不幸失恋了，请告诉我，我会帮助你摆脱困境，真的，请联系我啦！

China's plan to cut energy intensity by 20 percent and pollutant discharges by 10 percent between 2006 and 2010 is a case in point.

中国计划在2006年到2010间降低20%的能源强度和减少10%的主要污染物排放，就是一个这样的例子。