- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Reconstruction of image sequences from ungated and scanning-aberrated laser scanning microscopy images of the beating heart
摘要： Fluorescence laser-scanning microscopy is a well-established imaging technique in biology, available in many imaging facilities to investigate structures within live animal embryos such as zebrafish. Laser scanning microscopes (LSM) are limited when used to study dynamic heart morphology or function. Despite their ability to resolve static cardiac structures, the fast motion of the beating heart introduces severe artifacts in the scanned images and gating the acquisitions to the heartbeat is difficult to implement on traditional microscopes. Furthermore, although alternative high-speed imaging instruments exist, they are not widely available (due to cost or hardware complications), putting dynamic cardio-vascular imaging off-limits for many researchers. Here, we propose a method that allows imaging the beating heart on conventional LSMs. Our approach takes a set of images containing scanning aberrations, each triggered at an arbitrary time in the cardiac cycle, and assembles an image sequence that covers a single cardiac heartbeat. The steps are: (i) frame sorting by solving a traveling salesman problem; (ii) heartbeat duration estimation; and (iii) scan-delay compensation via space-time resampling. We characterize the performance of our method on synthetic data under several light intensities and scanning speeds. We further illustrate our method's applicability on experimental images acquired in live zebrafish larvae, and show that the reconstruction quality approaches that of fast, state-of-the-art microscopes. Our technique opens the possibility of using LSMs to carry out studies of cardiac dynamics, without the need for prospective gating or fast microscopes.
关键词： cardiac imaging,scanning aberration compensation,laser scanning microscopy,zebrafish imaging,fast microscopy,combinatorial optimization,traveling salesman problem,image and video sampling,Computational microscopy,confocal microscopy
更新于2025-09-11 14:15:04
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A Simple and Rapid Method to Produce SERS Substrates Using Au Nanoparticles Prepared by Laser Ablation and DVD Template
摘要： Simple and highly sensitive SERS substrates were produced using Au nanoparticles (AuNPs) prepared by laser ablation in water and available Digital Video Discs (DVDs). We used the simple ‘‘drop-cast’’ method to deposit AuNPs on the grating pattern surface of a DVD in place of the other methods such as electrochemical deposition, electrophoretic deposition and sputtering method which require some more equipment. AuNPs were proposed to be synthesized in water by laser ablation to form a nearly circular AuNP stain of small size on a DVD surface. The protecting polycarbonate layer of a DVD was removed from the DVD surface. The bare metallic DVD surface was rinsed carefully with ethanol and distilled water. The width of tracks on a DVD surface is around 300 nm and distance between them is around 450 nm. We prepared AuNPs by pulsed laser ablation of a gold piece in distilled water. The colloidal gold nanoparticles were deposited on DVD templates. We studied to produce an effective layer of AuNPs on DVD template for SERS substrates (AuNPs/DVD). The average SERS enhancement factor of the AuNPs/DVD SERS substrates is about 106. The SERS substrates can detect SERS spectra of Malachite Green and Amoxicillin at low concentrations of around 0.1–1 ppm.
关键词： Surface enhanced Raman scattering (SERS),digital video disc (DVD),laser ablation
更新于2025-09-11 14:15:04
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[IEEE 2018 25th IEEE International Conference on Image Processing (ICIP) - Athens, Greece (2018.10.7-2018.10.10)] 2018 25th IEEE International Conference on Image Processing (ICIP) - No-Reference Stereoscopic Video Quality Assessment Algorithm Using Joint Motion and Depth Statistics
摘要： We propose a supervised no-reference (NR) quality assessment algorithm for assessing the perceptual quality of natural stereoscopic (S3D) videos. We empirically model the joint statistics of motion and depth subband coefficients of an S3D video frame using a Bivariate Generalized Gaussian Distribution (BGGD). We compute the BGGD model parameters (α, β) to estimate the statistical dependency strength and show the features are quality discriminative. We compute the popular 2D NR image quality assessment (IQA) model NIQE on a frame-by-frame basis for both views to estimate the spatial quality. The frame-level BGGD features and spatial features are consolidated and used with the corresponding S3D videos difference mean opinion score (DMOS) labels for supervised learning using support vector regression (SVR). The overall quality of an S3D video is computed by averaging the frame-level quality predictions of the constituent video frames. The proposed algorithm, dubbed Video QUality Evaluation using MOtion and DEpth Statistics (VQUEMODES) is shown to outperform the state-of-the-art methods when evaluated over the IRCCYN and LFOVIA S3D subjective quality assessment databases.
关键词： Stereoscopic Video,Perceptual Quality,Natural Scene Statistics
更新于2025-09-11 14:15:04
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[IEEE 2018 NASA/ESA Conference on Adaptive Hardware and Systems (AHS) - Edinburgh, United Kingdom (2018.8.6-2018.8.9)] 2018 NASA/ESA Conference on Adaptive Hardware and Systems (AHS) - Towards the design of smart video-surveillance system
摘要： Security and monitoring systems are increasingly demanding in terms of quality, reliability and ?exibility especially those dedicated to video surveillance. The aim of this study is to identify some limiting factors in the existing video-surveillance systems and to propose a set of best practices for developing a smart platform for a security monitoring system incorporating advanced techniques for video processing and analysis. In this work, we focus on the effect of the video quality on the biometric part of the video-surveillance systems for public security. In such systems, face detection and recognition from video sequences acquired from surveillance cameras, are challenging tasks, due to presence of strong illumination variations, noise, and changes in facial expressions. In this paper, we mainly focus on the illumination issue occurred in video surveillance. The low light video data is processed using a perceptual based approach, namely multi-scale Retinex method, to improve the video quality, followed by face detection. The experimental results demonstrate signi?cant performance improvement in face detection and recognition, by improving the illumination of video sequences over the unprocessed video data.
关键词： Retinex,face recognition,face detection,video surveillance,enhancement
更新于2025-09-11 14:15:04
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[IEEE 2018 25th IEEE International Conference on Image Processing (ICIP) - Athens, Greece (2018.10.7-2018.10.10)] 2018 25th IEEE International Conference on Image Processing (ICIP) - Light Field Image Compression Based on Convolutional Neural Networks and Linear Approximation
摘要： Computer vision applications such as refocusing, segmentation and classification become one of the most advanced imaging services. LightField (LF) imaging systems provide a rich semantic information of the scene. Using a dense set of cameras and microlens arrays (Plenoptic camera), the direction of each ray coming from the scene toward the LF capture system can be extracted and represented by spatial and angular coordinates. However, such imaging system induces many drawbacks including the large amount of data produced and complexity increase for scene representation. In this paper, we propose an efficient LF image coding scheme. This scheme first encodes a sparse set of views using the latest hybrid video encoder (JEM). Then, it estimates a second sparse set of views using a linear approximation. At the decoder side, we use a Deep Learning (DL) approach to estimate the whole LF image from the reconstructed sparse sets of views. Experimental results show that the proposed scheme provides higher visual quality and overcomes the state of the art LF image compression solution by 30% bitrate gain.
关键词： LightField,MachineLearning,future video coding,Linear approximation,CNN
更新于2025-09-11 14:15:04
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[IEEE 2018 IEEE 3rd International Conference on Image, Vision and Computing (ICIVC) - Chongqing (2018.6.27-2018.6.29)] 2018 IEEE 3rd International Conference on Image, Vision and Computing (ICIVC) - Detection of Vehicle Flow in Video Surveillance
摘要： Existing detection algorithms of vehicle flow in video detect moving objects by per pixel, so they may be corrupted by noises and the computational costs are high. In this paper, we propose a robust moving vehicle detection algorithm with background dictionary learning. An improved vehicle flow detection algorithm based on virtual regions and virtual lines is presented. To do this, we firstly divide an image into multiple image patches that have the same sizes. Each patch is an object or a background. Then, a background dictionary is learnt for each patch. The similarity between a patch and the background dictionary is measured, upon which a patch is distinguished as an object or a background. Additionally, the virtual detection line is used and combined into the virtual regions to detect the vehicles. Experimental results demonstrate the real-time and accuracy of the proposed detection algorithm.
关键词： background dictionary,video,Gaussian model,vehicle flow detection
更新于2025-09-10 09:29:36
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - An Effective Zoom-In Approach for Detecting DIM and Small Target Proposals in Satellite Imagery
摘要： Satellite high de?nition videos provide an opportunity to monitor moving targets over a large territory. However, the low spatial resolution and low contract of these videos make target detecting and tracking a challenging task. In this paper, we propose a zoom-in approach for detecting dim and small target proposals from each single frame of the videos to help with moving target tracking. Initialized by a coarse scale segmentation approach, dim and small targets are embedded in each superpixel due to limited size and weak signals. Similar superpixels are then merged using a graph-based approach based on the measurement of the overlap between their histograms. The background statistics becomes stronger and target pixels are more obvious in the merged superpixels, so that the target pixels can be extracted. Finally, the corresponding boundary box is generated for each spatially connected target pixels selected inside each superpixel. They form the dim and small target proposals. Experimental results show that our zoom-in scheme can generate less proposals with higher recall rate compared with state-of-the-art proposal extraction algorithms.
关键词： Target Proposal,Satellite High De?nition Video,Dim and Small Target Detection
更新于2025-09-10 09:29:36
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Protocol for Producing Three-Dimensional Infrared Video of Freezing in Plants
摘要： Freezing in plants can be monitored using infrared (IR) thermography, because when water freezes, it gives off heat. However, problems with color contrast make 2-dimensions (2D) infrared images somewhat difficult to interpret. Viewing an IR image or the video of plants freezing in 3 dimensions (3D) would allow a more accurate identification of sites for ice nucleation as well as the progression of freezing. In this paper, we demonstrate a relatively simple means to produce a 3D infrared video of a strawberry plant freezing. Strawberry is an economically important crop that is subjected to unexpected spring freeze events in many areas of the world. An accurate understanding of the freezing in strawberry will provide both breeders and growers with more economical ways to prevent any damage to plants during freezing conditions. The technique involves a positioning of two IR cameras at slightly different angles to film the strawberry freezing. The two video streams will be precisely synchronized using a screen capture software that records both cameras simultaneously. The recordings will then be imported into the imaging software and processed using an anaglyph technique. Using red-blue glasses, the 3D video will make it easier to determine the precise site of ice nucleation on leaf surfaces.
关键词： Infrared thermography,plant freezing,anaglyph,3-dimensional video,convergence,strawberry
更新于2025-09-10 09:29:36
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11.1: <i>Invited Paper:</i> Electrofluidic displays: Fast switching, Colorful, low power
摘要： Electrofluidic and electrowetting displays have been demonstrated since 2004 [1]. They have been subject to extensive investigation, and many of the problems associated with the electrowetting phenomenon were solved. However, new challenges are emerging, in need of a solution. Electrofluidic displays could (and should) play an important role in a growing collection of display technologies, and will add significantly to our interaction with our environment, but is important to understand exactly how to implement and apply this technology. Maybe even more important: How not to apply it. This paper aims to provide an overview of historic achievements and elaborate on more recent progress, while making clear the exciting possibilities of the technology. It will provide a good insight in the current state of the art, and offer guidelines on the factors influencing contrast, brightness and speed.
关键词： Electrowetting,color,reflectance,video-rate,low power
更新于2025-09-10 09:29:36
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Digital Holographic Display System with Large Screen Based on Viewing Window Movement for 3D Video Service
摘要： A holographic display system with a 22-inch LCD panel is developed to provide a wide viewing angle and large holographic 3D image. It is realized by steering a narrow viewing window resulting from a very large pixel pitch compared to the wave length of the laser light. Point light sources and a lens array make it possible to arbitrarily control the position of the viewing window for a moving observer. The holographic display provides both eyes of the observer with a holographic 3D image using two vertically placed LCD panels and a beam splitter to support the holographic stereogram.
关键词： Holographic display,large screen,3D video,wide angle,viewing window
更新于2025-09-10 09:29:36