SMPTE 2010年立体影视技术会议概况(下)

三、立体节目制作 1、关于辐辏与焦点调节冲突的新见解 在现有立体显示技术中,至今未得到有效解决的问题就是眼睛辐辏与焦点调节的冲突问题.辐辏是指双眼视轴的辐辏.如图1所示,当我们在看物体A时,双眼辐辏使物体影像落在视网膜相对应的位置,角θA被称为辐辏角.     

立体视觉的机制（下）：立体照相理论与实践讲座之六

立体视觉的机制（下）──立体照相理论与实践讲座之六董太和（浙江大学）二、生理因素生理学和生理光学对立体视觉有影响的因素计有下列４种，而且彼此之间具有完美的协同作用，其中双眼静停视差和单眼移动视差是形成立体视觉的基础。１．眼睛的调节在观察对象的时候，眼...     

立体照相原理（上）：立体照相理论与实践讲座之七

立体照相原理（上）立体照相理论与实践讲座之七董太和（浙江大学）一、一般要求由前两章所述，已知人之立体感影像的形成，系来自双眼间的间距所形人的视差、双眼光轴对目标的辐辏（集合），以及晶体的调节（聚焦）等几种功能。在两眼视网膜上形成的略有不同的影像。在大...     

眼视光学Worth双眼三级融像论对立体电影之启悟

医学中的眼视光学揭橥,人的双眼视觉包括非线性的三级,立体视觉是最高级别,但受制于第一级同步各视和第二级水平合像,与人眼屈光系统中的角膜、虹膜与瞳孔、晶状体不无瓜葛,很大程度上决定于视力、视度尤其人眼的像差。研究发现,双眼合像的效果并不一定优于单眼各视。除视差外,眼动特别是错视、幻视都会左右立体视觉。将立体电影与"3D"强行捆绑,系电影商业属性驱使的话语纷扰。     

SMPTE2010年立体影视技术会议概况（下）

在现有立体显示技术中,至今未得到有效解决的问题就是眼睛辐辏与焦点调节的冲突问题。辐辏是指双眼视轴的辐辏。如图1所示,当我们在看物体A时,双眼辐辏使物体影像落在视网膜相对应的位置,     

基于视差空间运动估计的高精度立体视觉定位

立体视觉定位算法的运动估计通常在3D欧式空间中进行,但由于特征点3D坐标的噪声各向异性且分布不均匀,3D重建在深度方向上比另两个方向上的准确性差,从而导致3D欧式空间运动估计精确不高.本文提出了一种新的基于视差空间运动估计的高精度立体视觉定位算法.算法首先采用视差空间4点闭环线性解法和RANSAC算法得到初始鲁棒运动估计和匹配内点.接着,利用新的视差空间再投影误差函数提出了基于LM算法的视差空间运动参数非线性优化方法,对初始运动参数进一步优化.视差空间噪声分布均匀且各向同性,本文的初始运动参数线性估计和非线性优化都在视差空间中进行且能达到全局最小.仿真实验和真实实验结果表明,本文算法能得到高精度的立体视觉定位结果,优于传统的3D欧式空间运动估计方法.     

零件的立体视觉测量和三维重建研究

本文采用立体视觉测量并结合三维重建的方法,解决了零件的非接触测量问题。首先,分析了立体视觉测量系统的组成结构,利用左、右2个摄像机分别采集零件信息,进而根据二者间的空间关系计算视差数据。其次,采用均值滤波方法去除零件图像噪声,为立体匹配创造条件,进而根据立体图像对二者间的极线关系求取视差。选择Bowyer算法对视差图像进行剖分和三维重建。试验结果表明,本文建立的方法可有效完成航空发动机的叶片零件测量,进而实现生动逼真的三维重建。     

基于小波图像融合的非对称失真立体图像质量评价方法

通过研究非对称失真立体图像人眼视觉感知特性,提出了一种基于小波图像融合的非对称失真立体图像质量客观评价方法.首先,采用固定尺寸块匹配方法得到原始立体图像块视差值,接着,根据该视差值的大小,同时结合非对称失真立体图像视觉感知特性,对匹配块进行小波融合得到原始融合图像和失真融合图像.最后,通过计算原始融合图像和失真融合图像...     

基于立体视觉的钢卷检测技术

本文提出了基于立体视觉的钢卷检测技术,利用双目立体视觉系统得到钢卷图像对,进行立体矫正和立体匹配获取视差图,利用视差图的深度信息,提出基于深度直方图的方法分割出目标钢卷。再根据三角测量原理计算出钢卷视差图中每个像素点的深度,从而获取钢卷的点云数据。对钢卷点云数据进行高斯滤波,圆柱特征拟合后,获得钢卷的空间几何信息和位置信息。实验结果表明,检测的钢卷坐标和钢卷真实坐标之间的误差在允许的范围(100mm)以内,并且检测效率大大提高。     

生理检测综合评价工作负担研究

以探索如何缓解人在知识密集型工作中的负担为目的,考虑作业者的集中力、紧张感、疲劳等关联为基准,对生理状态进行检测。定量评价由于高精度劳动量的积累而引起的脑电波、肌电位变化与视觉疲劳所产生的工作负担,同时采用音乐调节缓解工作负担。结果表明:作业者的工作负担随作业次数增加而增加,非熟练者明显高于熟练者。通过音乐调节降低精神与肌肉的紧张和疲劳,对缓解与减轻工作负担起到重要作用。     

Autostereoscopic three-dimensional display based on two parallax barriers

An autostereoscopic three-dimensional (3D) display composed of a flat-panel display, two parallax barriers, and a backlight panel is proposed. Parallax barrier 1, located between the backlight panel and the flat-panel display, divides the lights to create the perception of stereoscopic images. Parallax barrier 2, located between the flat-panel display and the viewers, acts as the function of decreasing the cross talk of the stereoscopic images. The operation principle of the display and the calculation equations for the parallax barriers are described in detail. An autostereoscopic 3D display prototype is developed. The prototype presents high-quality stereoscopic images. At the optimal viewing distance, it presents stereoscopic images without cross talk. At other viewing distances, it has less cross talk than a conventional autostereoscopic 3D display based on one parallax.     

Enlargement of viewing area of stereoscopic full-color LED display by use of a parallax barrier

In a stereoscopic full-color LED display by use of a parallax barrier, we discuss optimization of the viewing area, which depends on the width of the black regions between LEDs. Although conventional stereoscopic displays use a parallax barrier to permit the viewer to view stereoscopic images without any special glasses, their viewing area is restricted by crosstalk and the disappearing of pixels. Widening of the viewing area is examined by use of full-color panels with black regions having different widths. The optimum aperture ratio of the parallax barrier is obtained by analyzing the viewing area. An enlarged viewing area has been demonstrated by use of a 3-in-1 chip LED panel that has wider black regions than ordinary LED lamp cluster panels.     

Accommodative responses to stereoscopic three-dimensional display

Experimental examination of the accommodative responses to a stereoscopic 3-D display found that accommodation was elicited by convergence and moved to the stereoscopic distance of the 3-D image. Immediately after the depth of the target was changed, the magnitude of response was smaller than that for a real target, but when the subjects fixated on the 3-D images, the responses were in almost the same position as the position of 3-D images. Measurement of accommodation response time after the subjects viewed 3-D images showed an afteraffect on the far-to-near accommodation response. The results are discussed in terms of the mismatch of accommodation and convergence in stereoscopic 3-D images and of the interaction between accommodation and convergence in human eyes.     

fMRI analysis of excessive binocular disparity on the human brain

The aim of this study is to evaluate brain regions related with excessive binocular disparity that may be linked to stereoscopic visual fatigue. In stereoscopic displays, excessive binocular disparity may generate blurring or double vision in the stereovision and induce unnatural oscillations in accommodation and vergence. These phenomena may lead to visual fatigue and activation (or deactivation) of human brain related with sensory and eye movement functions. A functional magnetic resonance imaging (fMRI) method is used to investigate the effect of excessive binocular disparity on human brain. Subjective assessments of visual fatigue are also conducted with the same stimuli as the fMRI experiment. Based on the subjective assessment results, participants are classified into low‐ and high‐fatigue groups. From the fMRI experiments, the high‐fatigue group showed more activation at the intraparietal sulcus (IPS) than the low‐fatigue group, when viewing an excessive disparity stimulus. The results showed that the excessive binocular disparity stimulus may induce overload to the IPS region, which is related with stereo processing and saccadic eye movement. In addition, it could be possible to use fMRI as an objective measurement method for understanding the stereoscopic visual fatigue when stimuli with excessive binocular disparity are applied.     

一种基于人眼视觉特性的立体图像质量客观评价方法

通过模拟人眼视觉特性中的对比度敏感函数、多通道效应以及立体感知特性,提出了一种基于人眼视觉特性的立体图像质量客观评价方法.在评价左右图像质量时,利用小波变换模拟人眼视觉特性中的多通道效应,不同空间频带的小波系数按对比度敏感函数进行加权,左右图像质量度量采用Canberra $巨离.在评价立体感知时,则通过计算原始与测试...     

Liquid crystal-on-silicon implementation of the partial pixel three-dimensional display architecture

We report the implementation of a liquid crystal-on-silicon, three-dimensional (3-D) diffractive display based on the partial pixel architecture. The display generates multiple stereoscopic images that are perceived as a static 3-D scene with one-dimensional motion parallax in a manner that is functionally equivalent to a holographic stereogram. The images are created with diffraction gratings formed in a thin liquid crystal layer by fringing electric fields from transparent indium tin oxide interdigitated electrodes. The electrodes are controlled by an external drive signal that permits the 3-D scene to be turned on and off. The display has a contrast ratio of 5.8, which is limited principally by optical scatter caused by extraneous fringing fields. These scatter sources can be readily eliminated. The display reported herein is the first step toward a real-time partial pixel architecture display in which large numbers of dynamic gratings are independently controlled by underlying silicon drive circuitry.     

光栅立体印刷的成像原理及技术工艺

光栅可分为狭缝光栅、柱镜光栅和矩阵式光栅,其中柱镜光栅应用最为广泛,3种光栅成像原理各不相同,且各具优缺点,其应用领域也不相同。立体印刷的工艺流程主要包括原稿制作、制版、印刷、印后加工。研究制作高精度、高一致性的光栅,制定统一的产品标准,普及在线光栅印刷工艺,将成为未来立体印刷技术的主要发展方向。     

基于双目相机的光栅立体印刷图像合成

目的研究一种基于双目相机的光栅立体图像合成方法。方法首先用双目相机采集场景中2个观察角度的二维平面图像数据。基于双目立体视觉理论,采用一种鲁棒性较强的基于区域分割的图像匹配方法,得到精度较高的深度图。然后分析序列视差图像的成像模型,建立一种基于双目图像对生成序列视差图像的方法,得到连续角度等间隔的序列图像。最后基于柱镜光栅的光学特性形成的立体印刷图像编码规则,对序列视差图像进行纵向条纹抽样分割,等间隔的抽取每幅序列视差图像中的对应列实现光栅立体图像的合成。结果验证了该光栅立体图像合成方法的有效性。结论基于双目相机的光栅立体合成方法,可以使立体印刷产品实现个性化、便捷化的即时输出。     

Super deep 3D images from a 3D omnifocus video camera

When using stereographic image pairs to create three-dimensional (3D) images, a deep depth of field in the original scene enhances the depth perception in the 3D image. The omnifocus video camera has no depth of field limitations and produces images that are in focus throughout. By installing an attachment on the omnifocus video camera, real-time super deep stereoscopic pairs of video images were obtained. The deeper depth of field creates a larger perspective image shift, which makes greater demands on the binocular fusion of human vision. A means of reducing the perspective shift without harming the depth of field was found.