PET柱镜光栅立体成像技术研究进展

目的 介绍柱镜光栅立体成像技术的原理、特点及其研究和应用进展。方法 综述柱镜光栅立体成像技术中,柱镜光栅微结构设计、PET柱镜光栅挤出成型工艺、“Magic 3D”软件设计制作的研究现状及应用进展。重点阐述柱镜光栅立体成像技术的分类及其制作方法,并对柱镜光栅立体成像技术在包装中的应用进行阐述。结论 近年来,柱镜光栅立体成像技术方面取得了大量研究成果,推动了酒类包装、食品包装行业的迅速发展。良好的柱镜光栅加密处理使平面图像产生立体感,被包装产品的质量安全得到有效管控。柱镜光栅立体成像技术在酒类包装、食品包装等方面得到了广泛应用,也是未来电子包装、医药包装、广告领域的发展方向之一。     

柱透镜光栅式裸眼三维显示系统视区分析

分析基于柱透镜光栅的裸眼立体显示系统,并建立明确的观察区域几何模型。首先建立了柱透镜光栅式裸眼3D显示系统观察区域的几何模型,研究了柱透镜光栅板的分光作用,分析了柱透镜参数和观察距离、观察视角之间的关系;然后通过建立的几何模型,对形成的观察区域进行分析,得出了观察范围的表达式以及柱透镜参数、显示屏参数和观察范围之间的关系;最后引用质量因子概念结合主观评测方法对两台裸眼3D显示设备形成的观察区域内的图像质量进行评价。实验结果表明:根据建立的几何模型可以计算出裸眼3D显示器的最佳观察区域。本模型为自由立体显示器的最优设计和具体实现提供了参考。     

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。     

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。     

立体图对及其相机（上续）立体照相机理论及实践讲座之十

立体图对及其相机（上续）立体照相机理论及实践讲座之十董太和二、国对型立体照相及相机就立体照相之发展过程而言，至今仍不外两大类型，即图对型与光栅（柱镜）型两者。在应用上各有其优缺点。图对型立体照相制作方便，成像细腻，层次分明，观看时无闪像感，而且远近景...     

光栅立体印刷图像处理技术研究

在阐述光栅立体印刷成像原理的基础上,分析了单幅平面图像立体处理方法,并利用图像处理软件Pho-toShop结合实例,论述了平面图像立体处理的具体方法。     

浅析光栅立体印刷的应用

传统印刷只能再现三维立体景物的二维平面影像,从而丧失了纵深立体的感觉。通过探讨光栅立体设计原理,以再现三维立体的图像,以及制作光栅立体画像的技术方法,阐述了狭缝光栅法、柱镜光栅法成像方法,并着重介绍了光栅材料,讨论了光栅材料的选择及应用。     

3D印刷技术研究进展及其在防伪领域中的应用

综述了柱透镜光栅印刷技术和微透镜光栅印刷技术在国内外的研究现状及其在防伪领域中的应用,指出3D印刷技术未来的发展趋势为3D微透镜光栅动态成像技术、高线数光栅印刷技术、纸基3D直印光栅技术,这3种印刷技术均面临其发展瓶颈,如何解决其发展瓶颈将是未来研究的重点。     

立体印刷用柱镜光栅线数检测方法研究

目的研究一种快速准确检测立体印刷用柱镜光栅线数的方法。方法柱镜光栅固定在测试平台上,测头基座沿水平方向移动,同时保证测头上的触头在垂直方向始终保持与光栅表面接触;然后由计算机实时采集测头水平方向和垂直方向的位移,把数据保存到数据库,并在计算机屏幕上显示柱镜光栅表面曲线;最后把测头水平方向和垂直方向的位移数据代入数据处理算法,计算出被测光栅线数。结果以100线的柱镜光栅作为被测光栅进行测试,测试结果与传统方法检测的线数非常接近,并且能在60 s内完成测试。结论该方法避免了传统人工观测带来的误差,并把测试时间由300 s降至60 s,具有高效率、高稳定性和高可靠性的优点。     

一种光栅条纹图像非线性矫正算法的DSP实现

为消除由LED线光源所导致的光栅条纹图像背景灰度和幅度的不一致性,提出一种以DSP(TMS320DM6437)为主要元件构建的玻璃条纹图像矫正处理系统。基于"曲线拟合"矫正算法,研究光栅条纹图像的矫正方法,实现对玻璃条纹图像的实时矫正,得到典型缺陷条纹图像。实验结果表明:光栅条纹图像处理系统运行稳定可靠,在该系统上实现"曲线拟合"矫正算法满足实时性要求,也可使矫正后的非均匀度降低,与软件求解算法相比,该系统可提高条纹图像的处理速度。     

Stereoscopic imaging and computer vision of impinging fires by a single camera with a stereo adapter

In this article, the novelty of using a single camera for stereoscopic imaging and computer vision of fire dynamics has been described. Specifically, 3D surface topology of the fires can be reconstructed and visualized using stereoscopic methodology. The basic stereo apparatus used in the present study consists of a high‐resolution digital camera and a stereo adapter, which is mounted to the front filter ring of the camera. A pair of stereo images could therefore be formed through the same lens system and recorded simultaneously on the same charge coupled device (CCD) chip. The mechanism of using a stereo adapter for stereoscopic imaging and its geometry has been elaborated in detail. The digitally reconstructed 3D results have also been validated by optical stereoscopic viewing using a pair of electronic shutter glasses synchronized with a computer monitor. The results have demonstrated that the single camera technique is a very powerful and cost‐effective diagnostic tool for fire studies. © 2005 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 15, 114–122, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ima.20044     

Fluorescence intensity ratio stereoscopic transform

A novel approach to 3-D information processing of 2-D cell images is presented, called fluorescence intensity ratio stereoscopic transform (FIRST). Here, we describe its basic principle of image processing and show the results for the ratio of total internal reflection fluorescence (TIRF) to fluorescence intensity. A simple, intuitive transform algorithm would help us to easily obtain a clear stereoscopic image from two 2-D cell images with different fluorescence intensity. For this purpose, nonlinear evanescent-field (EF) imaging of cell-membrane surface and its intracellular structures by using on-chip grating coupler is achieved. This method enabled us to obtain cell images with different signal-to-background ratio and resolution under microfluidic environments. Specifically, we manipulated optic pathway to partially illuminate microscale objects within the microfluidic channel. These findings imply this method will enable selectively to detect optical signals of biomolecular interaction within the cell membrane in a controlled manner. Furthermore, we believe this approach will help to develop an optofluidic sensor for individually detecting dynamic behaviors of intracellular molecules in living cells under microfluidic cell culture environments.     

线聚焦光学相干层析术的研究

提出了一种高速光学相干层析(OCT)成像技术方案。利用柱面镜的成像特性将传统OCT的点聚焦成像模式改变为线聚焦成像模式,从而降低二维OCT图像的扫描维数,达到提高成像速度的目的。利用ZEMAX光学软件对系统进行光线追迹获得光束经过柱面镜后的聚焦情况。随后采用635nm的激光光源和柱面镜构建了实验系统,实验结果很好地验证了光线追迹仿真结果。     

Three-dimensional reconstruction of fracture surfaces

An original method is presented to improve fracture surface characterization through an accurate three-dimensional (3-D) reconstruction. The method, based on digital image-processing techniques, was developed under the Khoros system. The reconstruction technique is based upon the stereoscopic principle to extract the surface local elevations from the stereo-pair images. The fractographs that compose the stereo pair are obtained by scanning electron microscopy from two points of view by tilting the object at two observation angles. The first step of image processing is the alignment of the two images. Next, an iterative processing based on the cross-correlation operation builds a very dependable high resolution elevation map of the fracture surface. Finally, the elevation map can be used to provide a 3-D perspective view of the surface by using various visualization tools. Also, profiles and horizontal sections are generated by sectioning the 3-D reconstructed surface.     

Computer-generated holograms of a real three-dimensional object based on stereoscopic video images

A novel method of using stereoscopic video images to synthesize the computer-generated hologram (CGH) patterns of a real 3D object is proposed. Stereoscopic video images of a real 3D object are captured by a 3D camera system. Disparity maps between the captured stereo image pairs are estimated and from these estimated maps the depth data for each pixel of the object can be extracted on a frame basis. By using these depth data and original color images, hologram patterns of a real object can be computationally generated. In experiments, stereoscopic video images of a real 3D object, a wooden rhinoceros doll, are captured by using the Wasol 3D adapter system and its depth data are extracted from them. Then, CGH patterns of 1280 pixels x 1024 pixels are generated with these depth-annotated images of the wooden rhinoceros doll, and the CGH patterns are experimentally displayed via a holographic display system.     

Development of a real-time stereo TEM

We have developed a real-time stereo transmission electron microscope (TEM) with tilting illumination. This system allows us to observe three-dimensional (3-D) images directly with a video-rate of 1/30 s. The system comprises two electrostatic deflectors. The first, included in the illumination system, is able to illuminate a specimen at two oblique stereoscopic angles (left and right of the optical axis) up to ±2.3 °. The second deflector, in the imaging system, is used to correct the image separation caused by defocusing of the tilted illumination. These deflectors are operated in synchronization with an NTSC video signal output from a CCD camera to record left projections on odd fields and right projections on even fields. The time series of stereo pairs is transferred to a 3-D display that enables viewing of the 3-D images without special glasses. Real-time observation of ZnO particles demonstrated that 3-D images were clear even while moving the specimen. We applied this system to observing dislocations in an Al thin film.     

Three-dimensional tracking of multiple skin-colored regions by a moving stereoscopic system

A system that performs three-dimensional (3D) tracking of multiple skin-colored regions (SCRs) in images acquired by a calibrated, possibly moving stereoscopic rig is described. The system consists of a collection of techniques that permit the modeling and detection of SCRs, the determination of their temporal association in monocular image sequences, the establishment of their correspondence between stereo images, and the extraction of their 3D positions in a world-centered coordinate system. The development of these techniques has been motivated by the need for robust, near-real-time tracking performance. SCRs are detected by use of a Bayesian classifier that is trained with the aid of a novel technique. More specifically, the classifier is bootstrapped with a small set of training data. Then, as new images are being processed, an iterative training procedure is employed to refine the classifier. Furthermore, a technique is proposed to enable the classifier to cope with changes in illumination. Tracking of SCRs in time as well as matching of SCRs in the images of the employed stereo rig is performed through computationally inexpensive and robust techniques. One of the main characteristics of the skin-colored region tracker (SCRT) instrument is its ability to report the 3D positions of SCRs in a world-centered coordinate system by employing a possibly moving stereo rig with independently verging CCD cameras. The system operates on images of dimensions 640 x 480 pixels at a rate of 13 Hz on a conventional Pentium 4 processor at 1.8 GHz. Representative experimental results from the application of the SCRT to image sequences are also provided.