Novel, high-quality surface plasmon resonance microscopy

A surface plasmon resonance microscope capable of high-quality speckle-free imaging has been designed that uses a laser as a source. An inexpensive acoustic transducer is used to reduce speckle and other image artifacts arising from the use of illumination from an inexpensive laser pointer. The microscope is described and operation of the system demonstrated.     

计算流动显示——概念,原理及实现

计算流动显示是近年来在流体领域出现的一个新的研究方向,是计算流体力学、实验流体力学和科学计算可视化等领域的结合。本文介绍了其概念和原理,描述了一种简单高效的基于光线投射方法的光线跟踪方法,用于构造计算流场的干涉图、阴影图和纹影图,并给出了计算与实验结果的比较。     

Three-dimensional, wavefield imaging of broadband seismic array data

This paper describes an implementation of a three-component, three-dimensional plane wave migration method to image P-to-S converted waves that arrive following the direct P waves of teleseismic earthquakes. The programs described assume that the input data have been deconvolved to produce a set of vector impulse response functions with the initial P pulse centered at time 0. This method was implemented as three different application programs called pwstack, pwmig, and gridstacker. pwstack produces local-scale plane wave decompositions using the pseudostation concept. The output of pwstack is an estimate of the plane wave response over a grid of slowness vectors interpolated onto a regular grid in space. The Gaussian smoother that is used for the pseudostation method has the additional benefit of serving as a type of spatial antialiasing filter. The program called pwmig takes the output of pwstack and inverts the plane wave data for radial and transverse scattering potential using an inverse generalized Radon transform. Data can be back-projected using a conventional longitudinal, radial, transverse coordinate system or a novel depth-variable method that computes a transformation matrix linking each vector sample to an equivalent dipping-layer coordinate system at the corresponding scattering point. Because pwmig is a prestack method, a final program, gridstacker, is needed to stack data from multiple events that characterize real data. gridstacker is a general solution for stacking data with different grid geometries and variable data quality. Weighting functions can be defined externally by a user-supplied recipe or one can use a set of robust estimation methods coded in gridstacker. The programs are validated with simulation data produced by recently developed elastic finite-difference code and a model that simulates the edge of a subduction zone. Finally, I show an example of an application of these programs to image the western United States with the USArray.     

Three-dimensional surface mapping simulator: theory,capabilities and operation

The design of a software system is described which simulates active three-dimensional (3D) optical mensuration by a/lowing user input of the coefficients of an arbitrary-dimension 3D polynomial surface, geometrical parameters relating the relative orientations of the active (projector) and passive cameras, and the pattern (s) to be projected by the active camera. Outputs are the resulting passive image and corresponding surface map. This simulator provides a useful tool for exploring the theoretical, conceptual and practical bases underlying active stereo vision, and allows simple stereo-vision experiments without a large investment in camera, computer and optical hardware.     

Digital imaging,spectroscopy, and liquid crystals in a hand‐held,non‐invasive device to determine hemoglobin concentration

Abstract— Anemia is a significant public‐health concern both in the United States and throughout the world. This disorder of low hemoglobin concentration in the blood, which often lurks undetected for long periods, contributes significantly to mortality and morbidity and is a major cause of lost revenues from workforce shortfalls, particularly in developing countries where the incidence of anemia is higher due to malnutrition and parasitic disease. The gold standard for measuring hemoglobin is a blood test requiring phlebotomy and laboratory quantification. Current physical examination techniques and non‐invasive adjuncts for detecting anemia are not sensitive and are subject to user variability. There is an urgent need for a hand‐held device which can measure hemoglobin concentration accurately, inexpensively, and non‐invasively. The evolution of a device from its early inception, which analyzed color decomposition in a digital image of the eyelid, to its final version that is a light, inexpensive, hand‐held, non‐invasive device utilizing liquid crystals to delineate the spectroscopic characteristics of the reflected light from the palpebral conjunctiva (the inside of the lower eyelid which contains many small blood vessels) and determine hemoglobin concentration in the circulating blood will be discussed. The future refinements required for bringing such a device to the market will also be discussed.     

Luminescent quantum dot-bioconjugates in immunoassays, FRET, biosensing, and imaging applications

Colloidal semiconductor nanocrystals (quantum dots, QDs), such as CdSe-ZnS core-shell, are highly luminescent and stable inorganic fluorophores that represent a promising alternative to organic dyes for a variety of biotechnological applications. They show size-tunable narrow photoluminescence spectra spanning nearly the full visible region of the optical spectrum for QDs with CdSe cores. We have developed several approaches to conjugate either one type or a combination of biologically distinct proteins to CdSe-ZnS core-shell QDs rendered water-soluble by surface ligation with dihydrolipoic acid (DHLA) groups. QD-protein conjugates prepared using these approaches were found to exhibit high specificity and stability in immunoassays and in Förster resonance energy transfer (FRET) assays as well as in prototype QD bioconjugate sensors. Tunable QD emission over a wide range of wavelengths permitted effective tuning of the degree of energy overlap between the QD donor and an acceptor dye, allowing control over the rate of FRET. Additionally, we have used these QD-bioconjugates in live cell labeling. These hybrid bioinorganic conjugates represent a promising tool for use in many biotechnological applications.     

Medical Images Simulation, Storage, and Processing on the European DataGrid Testbed

The European 1ST DataGrid project was a pioneer in identifying the medical imaging field as an application domain that can benefit from Grid technologies. This paper describes how and for which purposes medical imaging applications can be Grid-enabled. Applications that have been deployed on the DataGrid testbed and middleware are described. They relate to medical image manipulation, including image production, secured image storage, and image processing. Results show that Grid technologies are still in their youth to address all issues related to complex medical imaging applications. If the benefit of Grid enabling for some medical applications is clear, there remain opened research and technical issues to develop and integrate all necessary services.     

磁共振并行成像技术综述

介绍了常用的磁共振成像加速方法,其中并行成像尤为重要,因为它可以和其他加速方法互补;还介绍了5种常见的并行成像方法:利用局部灵敏度的部分并行成像、灵敏度编码、空间谐波同时获取、泛化自校正部分并行获取、与基于阵列线圈灵敏度的并行编码与复原.最后,讨论了这5种方法的互相联系,以及在工业上的应用,并展望了动态成像和非笛卡尔坐...     

一种红外成像检测系统设计

红外成像系统的性能检测是产品质量的重要保证,本文介绍了一种红外成像系统的检测设备的设计,通过设计一定特征的红外目标图像,检测红外成像系统的成像功能,同时检测红外成像系统的分辨率、成像坏元等关键性指标,通过检测系统控制设计保证检测系统输出的红外图像的温度阈值范围和质量满足被测对象的要求,并能够提供可设置的图像,实现了对红外成像系统的功能和性能检测。检测系统温度分辨率不大于0.2度,图像相对畸变2%,目标运动精度不大于0.05度,光能分布不均匀度不大于10%,视场角不小于8度。     

Recording,processing, and analysis of digital high-speed sequences in glottography

A new high-speed system for recording, processing, and analyzing vocal fold vibrations has been developed. Results obtained with this system are discussed from the technical and the medical points of view. Laryngeal movement can be recorded with a digital high-speed camera, at a maximum speed of about 5 600 frames/s and the sequence can contain as many as 8 192 single frames. Application specific software for adaptive, semiautomatic, motion analysis is used to calculate and plot the glottograms for selected points on each vocal cord. From the data obtained, we can calculate speed, acceleration rates, the fundamental frequency, amplitudes, and perturbation parameters. This approach to laryngeal examination, based on the digital films, motion plots and characteristic statistics, is a practicable method that promotes the possibilities of quantitative and graphic analysis of the moving vocal folds and overcomes the disadvantages of the currently common examination methods.     

A multimodal temporal panorama approach for moving vehicle detection,reconstruction and classification

Moving vehicle detection and classification using multimodal data is a challenging task in data collection, audio-visual alignment, data labeling and feature selection under uncontrolled environments with occlusions, motion blurs, varying image resolutions and perspective distortions. In this work, we propose an effective multimodal temporal panorama approach for moving vehicle detection and classification using a novel long-range audio-visual sensing system. A new audio-visual vehicle (AVV) dataset is created, which features automatic vehicle detection and audio-visual alignment, accurate vehicle extraction and reconstruction, and efficient data labeling. In particular, vehicles’ visual images are reconstructed once detected in order to remove most of the occlusions, motion blurs, and variations of perspective views. Multimodal audio-visual features are extracted, including global geometric features (aspect ratios, profiles), local structure features (HOGs), as well various audio features (MFCCs, etc.). Using radial-based SVMs, the effectiveness of the integration of these multimodal features is thoroughly and systematically studied. The concept of MTP may not be only limited to visual, motion and audio modalities; it could also be applicable to other sensing modalities that can obtain data in the temporal domain.     

Measure theoretic imaging,with an example employing magnetic resonance input

We present a new medical imaging principle which allows reconstruction of images (from the output of a general digital imaging technology) whose contrast is based on a fundamentally different mathematical mechanism than that of standard images. These images have the useful property that they are capable of exhibiting high contrast between tissues which in currently produced images necessarily have low contrast. The meaning of these images, and their general place in the context of present image generation techniques, is most naturally expressed in the formalism of measure theory. The property actually imaged is derived from a probability measure associated with the mapping which expresses the output of the imaging technology. It also has a nonprobabilistic interpretation as a generalization of the Jacobian, specifically, the Radon-Nikodym derivative. In particular, unlike standard images, contrast is independent of the metric in the space of physical signals that the imaging technology associates with points of the region to be imaged. Images based on this approach using magnetic resonance input are presented.     

计算成像前沿进展

计算成像是融合光学硬件、图像传感器和算法软件于一体的新一代成像技术,突破了传统成像技术信息获取深度(高动态范围、低照度)、广度(光谱、光场、3维)的瓶颈。本文以计算成像的新设计方法、新算法和应用场景为主线,通过综合国内外文献和相关报道来梳理该领域的主要进展。从端到端光学算法联合设计、高动态范围成像、光场成像、光谱成像、无透镜成像、低照度成像、3维成像和计算摄影等研究方向,重点论述计算成像领域的发展现状、前沿动态、热点问题和趋势。端到端光学算法联合设计包括了可微的衍射光学模型、折射光学模型以及基于可微光线追踪的复杂透镜的模型。高动态范围光学成像从原理到光学调制、多次曝光、多传感器融合以及算法等层面阐述不同方法的优点与缺点以及产业应用。光场成像阐述了基于光场的3维重建技术在超分辨、深度估计和3维尺寸测量等方面国内外的研究进展和产业应用,以及光场在粒子测速及3维火焰重构领域的研究进展。光谱成像阐述了当前多通道滤光片,基于深度学习和波长响应曲线求逆问题,以及衍射光栅、多路复用和超表面等优化实现高光谱的获取。无透镜成像包括平面光学元件的设计和优化,以及图像的高质量重建算法。低照度成像包括低照度情况下基于单帧、多帧、闪光灯和新型传感器的图像噪声去除等。3维成像主要包括针对基于主动方法的深度获取的困难的最新的解决方案,这些困难包括强的环境光干扰(如太阳光)、强的非直接光干扰(如凹面的互反射、雾天的散射)等。计算摄影学是计算成像的一个分支学科,从传统摄影学发展而来,更侧重于使用数字计算的方式进行图像拍摄。在光学镜片的物理尺寸、图像质量受限的情况下,如何使用合理的计算资源,绘制出用户最满意的图像是其主要研究和应用方向。     

Art,science, and appearance in HDR

Abstract— High‐dynamic‐range (HDR) image capture and display has become an important engineering topic. The discipline of reproducing scenes with a high range of luminances has a five‐century history that includes painting, photography, electronic imaging, and image processing. HDR images are superior to conventional images. There are two fundamental scientific issues that control HDR image capture and reproduction. The first is the range of information that can be measured using different techniques. The second is the range of image information that can be utilized by humans. Optical veiling glare severely limits the range of luminance that can be captured and seen. It is the improved quantization of digital data and the preservation of the scene's spatial information that causes the improvement in quality in HDR reproductions.     

Measurement and analysis on the accommodation responses to real‐mode,virtual‐mode,and focused‐mode integral imaging display

Integral imaging has three display modes including real mode, virtual mode, and focused mode, and each mode has unique display characteristics. In this paper, the accommodation responses to the three‐dimensional (3‐D) targets reconstructed by each mode of the integral imaging display were measured and statistically analyzed. Through the least square method, standard deviation analysis, and t‐test analysis, we found that the accommodation responses to the 3‐D target reconstructed by the focused mode was more similar to that of the real target on the same depth position. Moreover, the closer to the central depth plane was, the steadier accommodation response 3‐D targets could provide. These statistical analysis results are helpful to the design of integral imaging display device.     

Dr TIM: Ray-tracer TIM,with additional specialist scientific capabilities

We describe several extensions to TIM, a raytracing program for ray-optics research. These include relativistic raytracing; simulation of the external appearance of Eaton lenses, Luneburg lenses and generalised focusing gradient-index lens (GGRIN) lenses, which are types of perfect imaging devices; raytracing through interfaces between spaces with different optical metrics; and refraction with generalised confocal lenslet arrays, which are particularly versatile METATOYs.     

Application of Digital Manuals with a Retinal Imaging Display in Manufacturing: Behavioral,Physiological, and Psychological Effects on Workers

This study analyses the behavioral, physiological, and psychological effects of digital manuals presented by a retinal imaging display (RID) on workers in the manufacturing industry. An RID consists of wearable glasses that enable users to view a digital image overlaying the real world. We conducted an experiment in which subjects assembled an object by referring to different types of manuals. The experimental results suggest that an RID enables users to conveniently examine real objects against information in the manual, reduces the information‐processing load while performing tasks, and supports effortless performance of tasks. However, using a monochrome picture manual with an RID increases the information‐processing load. On the other hand, a full‐color RID movie manual generates additional responses in users, such as psychological satisfaction.     

定量磁共振图像的深度学习重建方法进展

磁共振成像是一种应用广泛的无创医学成像方法,因其丰富的软组织对比度可以成像人体几乎所有内部结构,包括器官、骨骼、肌肉和血管,已成为临床医学影像诊断的利器。然而磁共振成像存在两大公认的瓶颈：成像速度慢、扫描操作烦琐。深度学习给磁共振成像带来莫大的契机,给传统磁共振加速成像带来新的可能。鉴于该领域的快速发展性质,本文旨在总结文献中报道的大量深度学习和磁共振图像重建相结合的方法,以更好地了解该领域。本文简单介绍磁共振成像在多通道线圈接收的并行加速和压缩感知加速下的深度学习重建方法,其中单对比度图像可通过多通道接收线圈提供的冗余度用于加速,多对比度图像可额外使用不同对比度图像这一维度用于加速,动态图像与多对比度图像类似可额外使用时间维度用于加速,本文也将介绍深度学习在这些方面的发展。随着磁共振成像近年来由定性多对比度成像向定量多参数成像的发展,其中定量成像的图像中可内含多对比度图像,如何借用深度学习提供的能力将定性多对比度图像映射到参数图也是一个难点,近年来这一方向也获得了较快的发展,文中也将针对这方面内容进行调研并介绍。针对上述内容,分别介绍国际研究现状和国内研究现状,拟更好地总结国内外研究的发展的异同和趋势。最后对深度学习助力定量磁共振成像方面进行了展望。     

在体生物光学成像技术的研究进展

在体生物发光成像和在体荧光成像是近年来新兴的在体生物光学成像技术, 能够无损实时动态监测被标记细胞在活体小动物体内的活动及反应, 在肿瘤检测、基因表达、蛋白质分子检测、药物受体定位、药物筛选和药物疗效评价等方面具有很大的应用潜力. 本文详细介绍了在体生物发光成像和在体荧光成像的特点、系统及应用, 比较了它们的异同, 综述了在体生物光学成像技术的基本原理和应用领域, 讨论了将其应用于临床的进一步发展方向.