基于OGRE的汉字渲染方案

OGRE（object-oriented graphic render engine）作为一种通用的图形渲染引擎并不提供专门针对汉字的渲染方案。汉字字符与英文字符存在很大差别,不能简单套用英文字符的渲染方法,分析了汉字在OGRE的场景中的3种不同的渲染方案。并在讨论和比较的基础上,深入的研究并实现了在现阶段比较有价值的方案,为进一步研究积累了经验。     

嵌入式双目立体视觉测距系统

设计和研究了一种基于S3C2440硬件平台和嵌入式Linux双目立体视觉测距系统.该系统通过使用两个USB摄像头同步采集图像数据,并利用OpenCV对采集的两幅图像的数据进行处理,计算目标物在两幅图像中的像素偏差,进而算出目标物到摄像头平面的距离,在论文中以车牌作为目标物.同时该系统用Qt/Embedded实现LED实时显示图像和数据.整个系统建立在嵌入式架构上,能独立完成图像采集,数据处理,实时显示等功能.只要改变定位算法,则能测出任意目标物的距离.     

基于深度学习与双目立体视觉的物体管理应用

利用搭载双目摄像机与GPS设备,提出了一种基于深度学习与双目立体视觉的物体管理方案。首先用智能眼睛拍摄照片,并利用GPS获取智能眼睛所在的位置,然后利用卷积神经网络(CNN)中的FAST-RCNN对拍摄照片进行物体识别,获取照片中的物体,再利用双目立体视觉技术中的SGBM算法,获取照片中的物体相对与摄像机的坐标。利用拍摄者的GPS与物体相对拍摄者的坐标,就可以获取物体的坐标,从而获取物品的位置,实现管理物体的功能。     

立体显示的双目模型算法及实现

三维立体显示技术是虚拟现实的关键技术,也是虚拟现实系统必不可少的基本条件,而深度感的正确形成又是立体显示技术的关键。介绍了采用体视原理进行自由立体显示的两种投影系统,并对照了各自的特征。分析了汇聚式双目系统的误差,给出了平行双目投影系统的算法推导和OpenGL的实现。最终以实验印证了算法的可靠性和准确性。     

基于双目视觉技术的线路安全测距研究

为了精确地实现输电线路障碍测距，提出一种双目视觉的线路障碍安全测距方法。在分析双目视觉原理基础上，通过摄像机标定、立体校正、立体匹配等步骤实现测距。为了验证方案的可行性，搭建双目视觉巡检机器人，并模拟真实输电线路进行测距。结果表明，构建的双目视觉方案可实现输电线路障碍的高精度测距，且精度误差不超过3%,说明该方法可行，可用于机器人输电线路巡检。     

双目立体视觉和编码结构光相结合的三维重建方法

提出了一种双目立体视觉和编码结构光相结合的三维重建方法。为了降低单纯双目立体视觉方法中稠密对应点匹配问题的复杂度,同时回避单纯编码结构光法中的投影仪标定难题,该方法将编码结构光条纹带来的空间约束引入双目立体视觉方法中。实验实现了物体表面的重建,且算法复杂度和实现难度较低。     

双目摄像头立体视觉标定及畸变校正研究

为了提高立体视觉系统中的精度,本文提出了一种基于显隐的畸变校正模型。首先在世界坐标中对双目摄像头进行立体标定,然后采用基于显隐的畸变校正模型对双目摄像头采集的图像进行处理,实验结果表明,本文提出的一种基于显隐的畸变校正模型切实有效,且效果良好。     

多目立体视觉在工业测量中的应用研究

以双目立体视觉系统为基础，提出了一种多目立体视觉测量的方法。该方法利用摄像机旋转来获取多幅图像，利用这些立体图像对中对应特征点的视差得到物体的深度信息，达到多目测量的目的，通过实验并与双目立体视觉相比较，验证了其在摄像机标定和提高测量结果精度方面的优越性。     

三维立体显示综述

按基本工作原理是否为双目视差将三维立体显示分为两大类。基于双目视差原理的三维立体显示主要有眼镜/头盔式立体显示和光栅式自由立体显示,这类三维立体显示的技术相对成熟并有相应产品;非基于双目视差原理的三维立体显示主要有全息立体显示、集成成像立体显示和体显示等,这类三维立体显示的技术较不成熟,大多没有相应产品。对这些三维立体显示的器件结构、工作原理以及各自的特性进行了阐述。     

基于计算机三维立体视差映射的双目立体成像研究

基于计算机三维立体视差映射的双目立体成像涉及计算机视觉、模式识别、计算机图形学等领域中许多具有挑战性的研究问题。主要存在的问题是所成的立体图像仍不够逼真和自然,人们对人眼的功能以及双目立体成像模型的了解还不够彻底,立体图像对的获取还有一些难题没有得到较好的解决。该文提出了一种已建三维模型的情况下立体图像生成方法。介绍了三维软件中如何利用摄像机对象生成双目立体图像,研究了影响立体效果的几个重要因素,包括目标摄像机与三维模型的位置关系、镜头距离、成像位置的控制等内容。这些工作基于计算机三维立体视差映射的双目立体成像推向深入,也为双目立体成像在可视化立体展示中的应用提供了理论和技术上的支撑。     

虚拟现实近视干预疗法的原理研究与实现方法

本文主要是分析虚拟现实技术对近视治疗的效果,在实验基础上第一次提出了一种全新的近视治疗方法--“虚拟现实近视干预疗法”,即用医学上的双眼合像法结合虚拟现实技术来治疗近视。本文围绕虚拟现实近视干预疗法的原理研究及实现方法进行探讨;分析并阐述了这一医疗方法涉及到的三个理论基础：医学上的双眼合像的理论、非交叉视差形成的沉浸感、根据儿童患者设计的治疗参数;介绍了虚拟现实近视干预疗法的实现方法。用VisualC＋＋和OpenIn-ventor设计编写了能吸引儿童注意力的用立体眼镜观看的立体显示治疗软件,该软件中的图像具有远近移动、立体显示、人机交互等效果和功能。本文为近视的治疗提供了一个有益的创新,在理论和实践上都是十分有意义的
的。     

Quality assessment for virtual reality technology based on real scene

Virtual reality technology is a new display technology, which provides users with real viewing experience. As known, most of the virtual reality display through stereoscopic images. However, image quality will be influenced by the collection, storage and transmission process. If the stereoscopic image quality in the virtual reality technology is seriously damaged, the user will feel uncomfortable, and this can even cause healthy problems. In this paper, we establish a set of accurate and effective evaluations for the virtual reality. In the preprocessing, we segment the original reference and distorted image into binocular regions and monocular regions. Then, the Information-weighted SSIM (IW-SSIM) or Information-weighted PSNR (IW-PSNR) values over the monocular regions are applied to obtain the IW-score. At the same time, the Stereo-weighted-SSIM (SW-SSIM) or Stereo-weighted-PSNR (SW-PSNR) can be used to calculate the SW-score. Finally, we pool the stereoscopic images score by combing the IW-score and SW-score. Experiments show that our method is very consistent with human subjective judgment standard in the evaluation of virtual reality technology.

     

Depth perception for moving images shown on a large LED display with an aperture grille

Abstract— A type of depth illusion created by the use of an aperture grille is reported. When viewing a moving target through multiple slits, a movement with depth is perceived, which was originally reported (see Ref. 11). The binocular delay is considered to cause a virtual disparity between both perspective images with apparent movement. By using an LED display with an aperture grille as a stereoscopic display, perceived distance caused by a binocular delay has been measured. The measured distance is compared with the perceived distance for stereoscopic still images shown on a stereoscopic LED panel. The comparison supported that the binocular delay is converted into binocular disparity. Furthermore, pair‐comparison tests were conducted to investigate depth impressions. It was found that use of an aperture grille improves depth impression for a movie that was taken with a laterally moving camera.     

Judgments of the distance to nearby virtual objects: interaction of viewing conditions and accommodative demand

Ten subjects adjusted a real-object probe to match the distance of nearby virtual objects optically presented via a see-through, helmet-mounted display. Monocular, binocular, and stereoscopic viewing conditions were used with two levels of required focus. Observed errors may be related to changes in the subjects' binocular convergence. The results suggest ways in which virtual objects may be presented with improved spatial fidelity.     

考虑双目竞争视觉现象的非对称失真立体图像质量评价方法

目的 现有方法存在特征提取时间过长、非对称失真图像预测准确性不高的问题,同时少有工作对非对称失真与对称失真立体图像的分类进行研究,为此提出了基于双目竞争的非对称失真立体图像质量评价方法。方法 依据双目竞争的视觉现象,利用非对称失真立体图像两个视点的图像质量衰减程度的不同,生成单目图像特征的融合系数,融合从左右视点图像中提取的灰度空间特征与HSV （hue-saturation-value）彩色空间特征。同时,量化两个视点图像在结构、信息量和质量衰减程度等多方面的差异,获得双目差异特征。并且将双目融合特征与双目差异特征级联为一个描述能力更强的立体图像质量感知特征向量,训练基于支持向量回归的特征—质量映射模型。此外,还利用双目差异特征训练基于支持向量分类模型的对称失真与非对称失真立体图像分类模型。结果 本文提出的质量预测模型在4个数据库上的SROCC （Spearman rank order correlation coefficient）和PLCC （Pearson linear correlation coefficient）均达到0.95以上,在3个非对称失真数据库上的均方根误差（root of mean square error,RMSE）取值均优于对比算法。在LIVE-II（LIVE 3D image quality database phase II）、IVC-I（Waterloo-IVC 3D image qualityassessment database phase I）和IVC-II （Waterloo-IVC 3D image quality assessment database phase II）这3个非对称失真立体图像测试数据库上的失真类型分类测试中,对称失真立体图像的分类准确率分别为89.91%、94.76%和98.97%,非对称失真立体图像的分类准确率分别为95.46%,92.64%和96.22%。结论 本文方法依据双目竞争的视觉现象融合左右视点图像的质量感知特征用于立体图像质量预测,能够提升非对称失真立体图像的评价准确性和鲁棒性。所提取双目差异性特征还能够用于将对称失真与非对称失真立体图像进行有效分类,分类准确性高。     

A method for reproducing apparent continuous depth in a stereoscopic display using “Depth‐Fused 3D” technology

Abstract— A new method that can present fine depth increments in a stereoscopic display is proposed. In typical stereoscopic displays, depth can be presented by binocular disparity, but binocular disparity of less than one pixel cannot be displayed because, in general, electronic displays have discrete pixels. We combined binocular disparity and modulation of the edge luminance in DFD (depth‐fused 3D) displays. In an experiment, the perceived depth could be continuously changed by modulating the edge luminance only. Therefore, continuous depth can be produced by combining binocular disparity and modulation of edge luminance distribution.     

Cognitive processes in complex tasks: introduction and discussion

This paper points out that the fusional limits of binocular stereoscopic viewing are an important factor, not only determining the reproduction range of stereoscopic images, but also the conformity between the stereoscopic display and stereoscopic vision. Experimental results showed that fusional limits increase in proportion to the field of view angle, and that they are affected not only by the size of the viewing target, but also by the effects that the environment has on the target. These findings explain the differences between binocular vision in real space and binocular vision in a stereoscopic display. Finally, the conditions under which observers arc able to view images of stereoscopic displays without excessive visual strain are discussed.     

Interactive stereoscopic displays

Interactive stereo displays allow for the existence of a natural interaction between the user and the stereo images depicted on the display. In the type of display discussed here, this interaction takes the form of tracking the user's head and hand/arm position. Sensing the user's head position allows for the creation of motion parallax information, an immersive depth cue that can be added to the binocular parallax already present in the display. Sensing the user's hand or arm position allows the user to manipulate the spatial attributes of virtual objects and scenes presented on the display, which can enhance spatial reasoning. Moreover, allowing the user to manipulate virtual objects may permit the creation of a sense of spatial relations among elements in the display via proprioception, which may augment the two parallax cues. The congruence among binocular parallax, motion parallax, and proprioception should increase the sense of depth in the display and increase viewing comfort, as well as enhance the ability of our intuitive reasoning system to make reasoned sense out of the perceptual information. These advantages should make interactive stereo displays, which may be classified as a form of cognitive enhancement display, the display of choice in the future.     

Human fusion range for polarized 3D display

If discrepancy between accommodation and convergence caused by a stereoscopic display exceeds fusion range of human eyes, viewers will see ghosting image, which leads to the loss of correct depth information and even causes severe visual fatigue. In this paper, an experiment aiming to investigate the binocular fusion range is conducted for a polarized 3D display. Two experimental trials are arranged to examine two aspects of fusion range including outward depth and inward depth. 3D modeling software is used to generate the test stereoscopic image pairs, which vary in depth by adjusting the separation between the virtual cameras. Angular parallax corresponding to the limit of fusion range is obtained by determining critical point of ghosting images. The experimental results show deviation between theoretical fusion range calculated by formula and experimental one.?0.223° to 0.275° represent critical fusion range for the polarized 3D display to avoid ghosting images.