Three-dimensional color display by projection-type composite holography

A new method of projection-type composite holography for displaying three-dimensional (3-D) color information has been developed. The basic concept and the results of the experiments are described. A model 3-D color display system for storing several kinds of colored cinematic information is presented as a practical application of the method. This method constructs the 3-D color image by synthesizing the reconstructed images which are projected on the unilaterally direction-selective screen from several holograms. The 3-D color information is recorded as 3N holograms on a roll film arranged in an arc, the center of which is located on the screen. To reconstruct the 3-D color information three kinds of laser beams (red, green, and blue) illuminate these 3N holograms under the same condition. All the reconstructed images from these 3N holograms are projected and synthesized on the unilaterally direction-selective screen. The direction-selective axis of the screen is set parallel to the direction of the film. Consequently the color components of the reconstructed images are diffusely reflected and the angular components are reflected back in the original direction. The human eye can recognize a 3-D color image in the viewing zone enlarged through the vertical diffusing effect of the screen.     

面向网络视频的三维全景展示技术*

针对当前网络视频形式单一、缺乏多元化的视频形式展示的问题,结合三维全景展示技术,提出了面向网络视频的三维全景展示技术系统方案。重点分析了系统方案中的全景图拼接技术以及基于Flash视频技术的三维全景展示技术,并给出了一个具体的网络视频的三维全景展示示例,实现在互联网上逼真的展示三维场景。该方法能通过Flash脚本编程将图片、视频、音频等有机地结合起来,为网络视频用户提供三维全景与用户交互,使用户获得更好的网络视频体验。     

Three-dimensional holographic image sensing and Integral imaging display

In this paper, we propose three-dimensional (3-D) holographic sensing, and computational/optical 3-D integral imaging reconstruction. We demonstrate experimentally that through the integral imaging technique, it is possible to reconstruct a full 3-D scene which has been obtained by digital holograms. Three-dimensional color objects can also be displayed optically in 3-D without convergence-accommodation conflict using a microlens array, and a two-dimensional (2-D) display panel illuminated by incoherent light. The proposed approach takes advantages of high resolution holographic sensing and robust 3-D integral imaging visualization.     

冷冻电镜单颗粒重构中的病毒三维显示

利用冷冻电镜显微技术和单颗粒三维重建方法获得BmCPV（家蚕质多角体）;CSBV（中蜂囊状幼虫病痛毒）;C6／36DNV（C6／36浓核病毒）的三维结构体数据,用空间低通滤波对体数据矢量场进行处理并进行三维显示,较之原来的显示,提高了信噪比,增强了显示稳定性与显示质量、病毒每个表面细节和轴上突起更加清晰可见。     

基于Proteus的核信号输入LCD处理显示单元

Proteus可实现单片机仿真,并提供软件调试功能,支持第三方的软件编译和调试环境,如Keil C51 uVision2。本设计是以89C51单片机为控制单位,建立点阵型LCD12864的坐标并点亮矩阵点,实现核信号在点阵型LCD12864和字符型LCD1602上同步显示。在Proteus软件中进行了仿真,得到了预期结果。     

基于ECDIS的船舶运动态势三维呈现

为保障多船舶近距离作业安全、提高船舶航行监控显示效果,设计和实现了船舶运动态势三维呈现子系统。通过从ECIDS获取船舶与近船目标的位置及运动参数等信息,解算出多船舶的运动态势参数,进而利用OpenGL技术实现船舶运动态势的三维呈现。演示结果表明,该子系统能有效地提供近距离多船舶运动态势的三维呈现,为船舶安全航行和作业提供决策辅助。     

Three-dimensional display rendering acceleration using occlusion camera reference images

Volumetric three-dimensional (3-D) displays allow the user to explore a 3-D scene free of joysticks, keyboards, goggles, or trackers. For non-trivial scenes, computing and transferring a 3-D image to the display takes hundreds of seconds, which is a serious bottleneck for many applications. We propose to represent the 3-D scene with an occlusion camera reference image (OCRI). The OCRI is a compact scene representation that stores only and all scene samples that are visible from a viewing volume centered at a reference viewpoint. The OCRI enables computing and transferring the 3-D image an order of magnitude faster than when the entire scene is processed. The OCRI approach can be readily applied to several volumetric display technologies; we have tested the OCRI approach with good results on a volumetric display that creates a 3-D image by projecting 2-D scene slices onto a rotating screen.     

Pulse compression techniques in nuclear medicine

A high-efficiency "chirped" linear array of pinholes for imaging a distribution of radioisotopes is described. The image is obtained in a coded or scrambled form, and then decoded using a dispersive surface acoustic wave delay line. Results of an optical simulation experiment are presented.     

Three-dimensional integral imaging display system based on negative lens array

An integral imaging display system based on negative lens array in real mode is proposed in this letter. Compared with the conventional integral imaging system with positive lens array, the negative one has a huge advantage on viewing angle. The minimum viewing angle of the imaging display system based on negative lens array is the maximum viewing angle of the positive one with the same parameters. And the imaging display system based on negative lens array can enhance the viewing angle to 180° with special parameters. Other parameters, such as resolution and depth-of-field, are the same in both systems. Another advantage is that the proposed imaging display system based on negative lens array can fill the image area gap between 0 and 2f. The feasibility of our proposed method is experimentally proved. This work has been supported by the National Natural Science Foundation of China (No.11474169) and the Hebei Provincial Science Foundation for Youths (No.F2016402115). E-mail:XXJiao@hebeu.edu.cn      

Fourier classification images in cardiac nuclear medicine

At present, the diagnosis of cardiac left ventricular regional wall motion abnormalities (RWMA) in nuclear medicine is aided mainly by phase images and amplitude images, which picture the spatial distribution of the phase and of the amplitude of the first harmonics of pixel time activity curves, respectively. However, they do not utilize other information contained in the original radionuclide images, and they do not offer a direct diagnostic interpretation of the data. The proposed Fourier classification images (FCI) overcome these deficiencies. Their pixel intensities express directly the diagnostic class of RWMA. The FCI pixel intensities are functions of pixel coordinates, Fourier features of pixel time activity curves, and their distribution parameters, and they are not limited by the first harmonics model. The derivation of the pixel classifier includes normalization transformation of coordinates and activities. Fourier analysis of raw image data, and teaching the computer by examples of already diagnosed cases with the help of discriminant analysis. FCI offer direct and robust diagnosis of RWMA, superior to that derived from phase and amplitude images, especially in the detection of mild RWMA.     

Three-dimensional display and analysis of tomographic volume images utilizing a varifocal mirror

Described is a system for the multidimensional display and analysis of tomographic images utilizing the principle of variable focal (varifocal) length optics. The display system uses a vibrating mirror in the form of an aluminized membrane stretched over a loudspeaker, coupled with a cathode ray tube (CRT) display monitor suspended face down over the mirror, plus the associated digital hardware to generate a space filling display. The mirror is made to vibrate back and forth, as a spherical cap, by exciting the loudspeaker with a 30 Hz sine wave. "Stacks" of 2-D tomographic images are displayed, one image at a time, on the CRT in synchrony with the mirror motion. Because of the changing focal length of the mirror and the integrating nature of the human eye-brain combination, the time sequence of 2-D images, displayed on the CRT face, appears as a 3-D image in the mirror. The system simplifies procedures such as: reviewing large amounts of 3-D image information, exploring volume images in three dimensions, and gaining an appreciation or understanding of three-dimensional shapes and spatial relationships. The display system facilitates operator interactivity, e.g., the user can point at structures within the volume image, remove selected image regions to more clearly visualize underlying structure, and control the orientation of brightened oblique planes through the volume.     

Three-dimensional guide-wire reconstruction from biplane image sequences for integrated display in 3-D vasculature

Using three-dimensional rotational X-ray angiography (3DRA), three-dimensional (3-D) information of the vasculature can be obtained prior to endovascular interventions. However, during interventions, the radiologist has to rely on fluoroscopy images to manipulate the guide wire. In order to take full advantage of the 3-D information from 3DRA data during endovascular interventions, a method is presented that yields an integrated display of the position of the guide wire and vasculature in 3-D. The method relies on an automated method that tracks the guide wire simultaneously in biplane fluoroscopy images. Based on the calibrated geometry of the C-arm, the 3-D guide-wire position is determined and visualized in the 3-D coordinate system of the vasculature. The method is evaluated in an intracranial anthropomorphic vascular phantom. The influence of the angle between projections, distortion correction of the projection images, and accuracy of geometry knowledge on the accuracy of 3-D guide-wire reconstruction from biplane images is determined. If the calibrated geometry information is used and the images are corrected for distortion, a mean distance to the reference standard of 0.42 mm and a tip distance of 0.65 mm is found, which means that accurate guide-wire reconstruction from biplane images can be performed.     

Restoration of gamma camera-based nuclear medicine images

Experiments were conducted using a Siemens Rota camera to study the applicability of two linear shift-invariant (LSI) filters, namely, the Wiener and power spectrum equalization filters, for restoration of planar projections and single-photon-emission computed tomography (SPECT) images. In the restoration scheme, the system transfer function, computed from a line source image, is modeled by a 2-D Gaussian function. The noise power spectrum is modeled as a constant for planar images and as a ramp for SPECT images. The filters have been applied to restore computer-simulated 1-D and 2-D projections and SPECT images of two simple phantoms, 2-D projections of two phantoms obtained from the Siemens Rota camera, and SPECT images of a cardiac phantom obtained from the Siemens Rota camera. The filters are shown to perform partial restoration. Considerable noise suppression and detail enhancement have been observed in the restored images. quantitative measurements such as root-mean-squared error and contrast ratio have been used for objective analysis of the results, which are encouraging.     

Application of II-VI materials to nuclear medicine

Semiconductor gamma-ray detector arrays made of II-VI materials such as CdTe or CdZnTe hold great promise for improving the spatial resolution and energy resolution of nuclear medicine imaging systems. This field has benefited greatly from technologies developed in infrared imaging. This report surveys the state of the art for producing high-resolution semiconductor arrays with emphasis on II-VI materials and considers the prospects for producing a semiconductor detector gamma camera. A number of practical designs are reviewed that make use of single-charge-carrier dominance effects to improve useful photopeak fraction and thus efficiency.     

Three-dimensional display from cross-sectional tomographic images: an application to magnetic resonance imaging

A system has been developed to facilitate three-dimensional visualizations of tomographic image data. Tomographic techniques yield parallel planes of data at discrete locations; thus, a series of images comprises a three-dimensional database. From this database, a system has been developed to perform three-dimensional calculations, measurements, and display. The system consists of a conventional two-dimensional video monitor, a digitizing tablet for user interaction and region-of-interest (ROI) definition, application-oriented computational software, and an image display system for true three-dimensional database visualization. The three-dimensional display makes use of a varifocal mirror system with vector graphics capability. Through the use of specialized contouring software, we illustrate the utility of this system in the specific examples of displays prepared from magnetic resonance (MR) images of the brain and carotid arteries. It can be concluded that this system will provide valuable diagnostic and physiologic information that will provide added insight into normal and abnormal structure and its relationship to function.     

Introduction to holospectral imaging in nuclear medicine for scatter subtraction

An approach to image analysis and processing, called holospectral imaging, is proposed for dealing with Compton scattering contamination in nuclear medicine imaging. The method requires that energy information be available for all detected photons. A set of frames (typically 16) representing the spatial distribution at different energies is then formed. The relationship between these energy frames is analyzed, and the original data is transformed into a series of eigenimages and eigenvalues. In this space it is possible to distinguish the specific contribution to the image of both primary and scattered photons and, in addition, noise. Under the hypothesis that the contribution of the primary photons dominates the image structure, a filtering process can be performed to reduce the scattered contamination. The proportion of scattered information removed by the filtering process is evaluated for all images and depends on the level of residual quantum noise, which is estimated from the size of the smaller eigenvalues. Results indicate a slight increase in the statistical noise but also an increase in contrast and greatly improved ability to quantitate the image.     

Two iterative image restoration algorithms with applications to nuclear medicine

Two methods for recovering an image that has been degraded while being processed are presented. The restoration problem is formulated as a constrained optimization problem in which a measure of smoothness based on the second derivatives of the restored image is maximized subject to the constraint that noise energy is equal to the energy in the difference between the distorted and blurred images. The approach is based on the Lagrange multiplier method. The first algorithm reduces the problem to the computation of few discrete Fourier transforms and allows control of the degree of sharpness and smoothness of the restored image. The second algorithm with weight matrices included allows the handling of edges and flat regions in the image in a pleasing manner for the human visual system. In this case the iterative conjugate gradient method is used in conjunction with the discrete Fourier transform to minimize the Lagrangian function. The application of these algorithms to nuclear medicine images is presented.     

Three-dimensional display and arbitrary region interactive segmentation of high-resolution virus capsids from cryo-electron microscopy single particle reconstruction

Recent advances in cryo-electron microscopy (cryo-EM) instrumentation and single particle reconstruction have created opportunities for high-throughput and high-resolution three-dimensional (3-D) structure determination of virus. In order to visualize and effectively understand the 3-D structure, we present a display method based on surface rendering, which has the function of 3-D arbitrary region interactive segmentation and quantitative analysis, and integrate them into a software package called CEM-3DVDSS (cryo-EM 3-D virus display and arbitrary region segmentation system). CEM-3DVDSS consists of a complete set of modular programs for 3-D display and segmentation of icosahedral virus, which is organized under a graphical user interface and provides user-friendly options. First, we convert volume data in the MRC format obtained by cryo-EM single particle reconstruction to the format of our own software; in the preprocessing step, the original volume data are compressed and a better vector dimension is found for controlling the speed and detail of display. Then, the new volume data can be displayed and segmented using CEM-3DVDSS. We demonstrate the applicability of CEM-3DVDSS by displaying the 3-D structures of 2.5 nm (resolution) BmCPV (Bombyx mori cytoplasmic polyhedrosis virus), 2.5 nm CSBV (Chinese Sacbrood bee virus) and 1.4 nm C6/36DNV (Densonucleosis virus). As a result, both the 3-D display speed and signal-to-noise ratio of CEM-3DVDSS are improved compared with the original method, and the segmentation results become precise and more intact with additional function of quantitative analysis of 3-D structure.