Using three-phase remote sensing images of China-Brazil Earth Resources Satellite 02B (CBERS02B) and Landsat-5 TM, tobacco field was extracted by the analysis of time series image based on the different phenological c...Using three-phase remote sensing images of China-Brazil Earth Resources Satellite 02B (CBERS02B) and Landsat-5 TM, tobacco field was extracted by the analysis of time series image based on the different phenological characteristics between tobacco and other crops. The spectral characteristics of tobacco and corn in luxuriant growth stage are very similar, which makes them difficult to be distinguished using a single-phase remote sensing image. Field film after tobacco seedlings transplanting can be used as significant sign to identify tobacco. Remote sensing interpre- tation map based on the fusion image of TM and CBERS02B's High-Resolution (HR) camera image was used as stan- dard reference material to evaluate the classification accuracy of Spectral Angle Mapper (SAM) and Maximum Like- lihood Classifier (MLC) for time series image based on full samples test method. SAM has higher classification accu- racy and stability than MLC in dealing with time series image. The accuracy and Kappa of tobacco coverage extracted by SAM are 83.4% and 0.692 respectively, which can achieve the accuracy required by tobacco coverage measurement in a large area.展开更多
How to deal with geometric distortion is an open problem when using the massive amount of satellite images at a national or global scale, especially for multi-temporal image analysis. In this paper, an algorithm is pr...How to deal with geometric distortion is an open problem when using the massive amount of satellite images at a national or global scale, especially for multi-temporal image analysis. In this paper, an algorithm is proposed to automatically rectify the geometric distortion of time-series CCD multi- spectral data of small constellation for environmental and disaster mitigation （HJ-1A/B） which was launched by China in 2008. In this algorithm, the area-based matching method was used to automatically search tie points firstly, and then the polynomial function was introduced to correct the systematic errors caused by the satellite motion along the roll, pitch and yaw direction. The improved orthorectification method was finally used to correct pixel displacement caused by off-nadir viewing of topography, which are random errors in the images and cannot be corrected by the polynomial equation. Nine scenes of level 2 HJ CCD images from one path/row were taken as the warp images to test the algorithm. The test result showed that the overall accuracy of the proposed algorithm was within 2 pixels （the average residuals were 37.8 m, and standard deviations were 19.8 m）. The accuracies of 45.96% validation points （VPs） were within 1 pixel and 90.33% VPs were within 2 pixels. The discussion showed that three main factors including the distortion patterns of HJ CCD images, pereent of cloud cover and the varying altitude of the satellite orbit may affect the search of tie points and the accuracy of results. Although the influence of varying altitude of the satellite orbits is less than the other factors, it is noted that detailed satellite altitude information should be given in the future to get a more precise result. The proposed algorithm should be an efficient tool for the geo-correction of HJ CCD multi-spectral images.展开更多
In the process of image transmission, the famous JPEG and JPEG-2000 compression methods need more transmission time as it is difficult for them to compress the image with a low compression rate. Recently the compresse...In the process of image transmission, the famous JPEG and JPEG-2000 compression methods need more transmission time as it is difficult for them to compress the image with a low compression rate. Recently the compressed sensing（CS） theory was proposed, which has earned great concern as it can compress an image with a low compression rate, meanwhile the original image can be perfectly reconstructed from only a few compressed data. The CS theory is used to transmit the high resolution astronomical image and build the simulation environment where there is communication between the satellite and the Earth. Number experimental results show that the CS theory can effectively reduce the image transmission and reconstruction time. Even with a very low compression rate, it still can recover a higher quality astronomical image than JPEG and JPEG-2000 compression methods.展开更多
Electrical impedance tomography(EIT)is a non-invasive imaging modality that generates real-time images by measuring tissue bioimpedance.It works by applying current and collecting voltage data to reconstruct images of...Electrical impedance tomography(EIT)is a non-invasive imaging modality that generates real-time images by measuring tissue bioimpedance.It works by applying current and collecting voltage data to reconstruct images of electrical conductivity,refl ecting tissue properties.[1]We aim to off er a comprehensive guide to the fundamental technology behind EIT and to explore its clinical applications across both pulmonary and extrapulmonary domains.展开更多
Although the image dehazing problem has received considerable attention over recent years,the existing models often prioritise performance at the expense of complexity,making them unsuitable for real-world application...Although the image dehazing problem has received considerable attention over recent years,the existing models often prioritise performance at the expense of complexity,making them unsuitable for real-world applications,which require algorithms to be deployed on resource constrained-devices.To address this challenge,we propose WaveLiteDehaze-Network(WLD-Net),an end-to-end dehazing model that delivers performance comparable to complex models while operating in real time and using significantly fewer parameters.This approach capitalises on the insight that haze predominantly affects low-frequency infor-mation.By exclusively processing the image in the frequency domain using discrete wavelet transform(DWT),we segregate the image into high and low frequencies and process them separately.This allows us to preserve high-frequency details and recover low-frequency components affected by haze,distinguishing our method from existing approaches that use spatial domain processing as the backbone,with DWT serving as an auxiliary component.DWT is applied at multiple levels for better in-formation retention while also accelerating computation by downsampling feature maps.Subsequently,a learning-based fusion mechanism reintegrates the processed frequencies to reconstruct the dehazed image.Experiments show that WLD-Net out-performs other low-parameter models on real-world hazy images and rivals much larger models,achieving the highest PSNR and SSIM scores on the O-Haze dataset.Qualitatively,the proposed method demonstrates its effectiveness in handling a diverse range of haze types,delivering visually pleasing results and robust performance,while also generalising well across different scenarios.With only 0.385 million parameters(more than 100 times smaller than comparable dehazing methods),WLD-Net processes 1024×1024 images in just 0.045 s,highlighting its applicability across various real-world scenarios.The code is available at https://github.com/AliMurtaza29/WLD-Net.展开更多
We investigate the spatial and temporal correlations of hot-electron generation in high-intensity laser interaction with massive and thin copper targets under conditions relevant to inertial confinement fusion.Using K...We investigate the spatial and temporal correlations of hot-electron generation in high-intensity laser interaction with massive and thin copper targets under conditions relevant to inertial confinement fusion.Using Ka time-resolved imaging,it is found that in the case of massive targets,the hot-electron generation follows the laser pulse intensity with a short delay needed for favorable plasma formation.Conversely,a significant delay in the x-ray emission compared with the laser pulse intensity profile is observed in the case of thin targets.Theoretical analysis and numerical simulations suggest that this is related to radiation preheating of the foil and the increase in hot-electron lifetime in a hot expanding plasma.展开更多
The optimal imaging time selection of ship targets for shore-based inverse synthetic aperture radar （ISAR） in high sea conditions is investigated. The optimal imaging time includes opti- mal imaging instants and opt...The optimal imaging time selection of ship targets for shore-based inverse synthetic aperture radar （ISAR） in high sea conditions is investigated. The optimal imaging time includes opti- mal imaging instants and optimal imaging duration. A novel method for optimal imaging instants selection based on the estimation of the Doppler centroid frequencies （DCFs） of a series of images obtained over continuous short durations is proposed. Combined with the optimal imaging duration selection scheme using the image contrast maximization criteria, this method can provide the ship images with the highest focus. Simulated and real data pro- cessing results verify the effectiveness of the proposed imaging method.展开更多
Electrical capacitance volume tomography(ECVT) is a recently-developed technique for real-time,non-invasive 3D monitoring of processes involving materials with strong contrasts in dielectric permittivity.This work is ...Electrical capacitance volume tomography(ECVT) is a recently-developed technique for real-time,non-invasive 3D monitoring of processes involving materials with strong contrasts in dielectric permittivity.This work is first application of the method to visualization of water flow in soil.We describe the principles behind the method,and then demonstrate its use with a simple laboratory infiltration experiment.32 ECVT sensors were installed on the sides of an empty PVC column.Water was poured into the column at a constant rate,and ECVT data were collected every second.The column was then packed with dry sand and again supplied with water at a constant rate with data collected every second.Data were analyzed to give bulk average water contents,which proved consistent with the water supply rates.Data were also analyzed to give 3D images(216 voxels) allowing visualization of the water distribution during the experiments.Result of this work shows that water infiltration into the soil,wall flow,progress of the unstable wetting front and the final water distribution are clearly visible.展开更多
A wide range of techniques has been developed to image biological samples at high spatial and temporal resolution.In this paper,we report recent results from deep-UV confocal fAuorescence microscopy to image inherent ...A wide range of techniques has been developed to image biological samples at high spatial and temporal resolution.In this paper,we report recent results from deep-UV confocal fAuorescence microscopy to image inherent emission from fuorophores such as tryptophan,and structured ilumination microscopy(SIM)of biological materials.One motivation for developing deep-UV fhuorescence imaging and SIM is to provide methods to complement our measurements in the emerging field of X-ray coherent diffractive imaging.展开更多
In our previous work, a novel algorithm to perform robust pose estimation was presented. The pose was estimated using points on the object to regions on image correspondence. The laboratory experiments conducted in th...In our previous work, a novel algorithm to perform robust pose estimation was presented. The pose was estimated using points on the object to regions on image correspondence. The laboratory experiments conducted in the previous work showed that the accuracy of the estimated pose was over 99% for position and 84% for orientation estimations respectively. However, for larger objects, the algorithm requires a high number of points to achieve the same accuracy. The requirement of higher number of points makes the algorithm, computationally intensive resulting in the algorithm infeasible for real-time computer vision applications. In this paper, the algorithm is parallelized to run on NVIDIA GPUs. The results indicate that even for objects having more than 2000 points, the algorithm can estimate the pose in real time for each frame of high-resolution videos.展开更多
Recently, Sandia Laboratories developed a neutron scatter camera to detect special nuclear materials. This camera exhibits the following advantages: high efficiency, direction discrimination, neutron-gamma discriminat...Recently, Sandia Laboratories developed a neutron scatter camera to detect special nuclear materials. This camera exhibits the following advantages: high efficiency, direction discrimination, neutron-gamma discrimination ability, and wide field of view. However, using the direct projection method, the angular resolution of this camera is limited by uncertainties in the energies estimated from pulse height and time of flight measurements. In this study, we established an eight-element neutron scatter camera and conducted the experiment with a ^(252)Cf neutron source. The results show that it has an angular resolution better than 8°(1s) and a detection efficiency of approximately 2.6′10-4. Using maximum likelihood expectation maximization method, the image artifact was eliminated, and the angular resolution was improved. We proposed an average scattering angle method to estimate the scattering energy of neutrons and Compton gamma rays. As such, we can obtain a recognizable image and energy spectrum of the source with some degradation of energy and image resolutions. Finally, a newly measured light response function based on the MPD^(-4) device was used for image reconstruction. Although we did not obtain a better result than that of the standard light response function, we have observed the effects of light response function on image reconstruction.展开更多
Ultrasound imaging-guided spinal puncture is highly desirable for the treat-ment of degenerative diseases of the spine,cerebrospinal fluid sampling,and spinal anesthesia administration due to its real-time and portabl...Ultrasound imaging-guided spinal puncture is highly desirable for the treat-ment of degenerative diseases of the spine,cerebrospinal fluid sampling,and spinal anesthesia administration due to its real-time and portable na-ture.However,conventional ultrasound imaging guidance methods image the target area from outside the body and obtain only two-dimensional(2D)images,making it very difficult to identify the puncture needle and under-stand the situation behind the vertebrae during the puncture process.Here,we present a new method for placing a 2D ultrasound array trans-ducer into the needle tip.The array has a stepped shape that fits well with the puncture needle,and real-time three-dimensional(3D)volumetric images can be obtained in the body in front of the needle as guidance dur-ing the puncture procedure.Our innovative transducer design and fabrica-tion method enable the integration of a 10-MHz,256-element 2D array transducer in the needle tip,leading to superior imaging resolution.The re-sults of in vitro and in vivo pig experiments demonstrate that the needle po-sition can be clearly identified and guided during the puncture process.This technology can improve the guidance accuracy and greatly reduce un-expected risks during puncture procedures,which has great potential in spinal punctures in clinical settings.展开更多
Imaging flow cytometry(IFC)combines the imaging capabilities of microscopy with the high throughput of flow cytometry,offering a promising solution for high-precision and high-throughput cell analysis in fields such a...Imaging flow cytometry(IFC)combines the imaging capabilities of microscopy with the high throughput of flow cytometry,offering a promising solution for high-precision and high-throughput cell analysis in fields such as biomedicine,green energy,and environmental monitoring.However,due to limitations in imaging framerate and realtime data processing,the real-time throughput of existing IFC systems has been restricted to approximately 1000-10,000 events per second(eps),which is insufficient for large-scale cell analysis.In this work,we demonstrate IFC with real-time throughput exceeding 1,000,000 eps by integrating optical time-stretch(OTS)imaging,microfluidic-based cell manipulation,and online image processing.Cells flowing at speeds up to 15 m/s are clearly imaged with a spatial resolution of 780 nm,and images of each individual cell are captured,stored,and analyzed.The capabilities and performance of our system are validated through the identification of malignancies in clinical colorectal samples.This work sets a new record for throughput in imaging flow cytometry,and we believe it has the potential to revolutionize cell analysis by enabling highly efficient,accurate,and intelligent measurement.展开更多
Biopolymer core-shell microspheres play a crucial role in various biomedical applications,including drug delivery,tissue engineering,and diagnostics.These applications require microparticles with consistent,well-contr...Biopolymer core-shell microspheres play a crucial role in various biomedical applications,including drug delivery,tissue engineering,and diagnostics.These applications require microparticles with consistent,well-controlled size and precise shape fidelity.However,achieving high-throughput synthesis of size and shape-controlled core-shell biopolymer microgels remains a significant challenge.Herein,we present a one-step process for the high-throughput generation of monodisperse,luminescent,chitosan alginate core-shell microspheres by a novel manipulation of a centrifugal microfluidic device.We utilized the pH sensitivity of chitosan and the ionic gelation properties of alginate to create well-defined core-shell morphologies.To address particle merging issues and promote uniform particle size generation,we introduced an innovative pulsed mode operation in our centrifugal microfluidics device.We also incorporated fluorescent,nitrogen-functionalized graphene quantum dots into the core-shell structures,thereby rendering them useful for real-time imaging,which is necessary for diagnostic and therapeutic applications.To enhance biocompatibility,the alginate solution was supplemented with fish gelatin(FG).The resulting microspheres exhibited excellent structural integrity maintaining their core-shell structure after 15 days.Biocompatibility was demonstrated by C2C12 cell viability exceeding 88%after 15 days and by bacterial viability reaching the same percentage after 2 days.The system demonstrates considerable scalability,allowing for the consistent production of large quantities of microspheres without compromising functionality.The streamlined and efficient methodology simplifies the production process while unlocking new possibilities in targeted therapies,tissue regeneration,and diagnostics.展开更多
Single-pixel imaging(SPI)is a promising technology for optical imaging beyond the visible spectrum,where commercial cameras are expensive or unavailable.However,limitations such as slow pattern projection rates and ti...Single-pixel imaging(SPI)is a promising technology for optical imaging beyond the visible spectrum,where commercial cameras are expensive or unavailable.However,limitations such as slow pattern projection rates and time-consuming reconstruction algorithms hinder its throughput for real-time imaging.Consequently,conventional SPI is inadequate for high-speed,high-resolution tasks.To address these challenges,we developed an ultrahigh-throughput single-pixel complex-field microscopy(SPCM)system utilizing frequency-comb acousto-optic coherent encoding(FACE).This system enables real-time complex-field monitoring in the non-visible domain.Operating at 1030 nm,our system achieves a record-high space-bandwidth-time product(SBP-T)of 1.3×10^(7),surpassing previous SPCM(~10^(4)),SPI(~10^(5)),and even certain types of commercial near-infrared cameras(~10^(6)).It supports real-time streaming at 1000 Hz with a frame size of 80×81 pixels and a lateral resolution of 3.76μm across an approximately 300μm field of view.We validated the system by imaging dynamic transparent scenes,including microfluidics,live microorganisms,chemical reactions,as well as imaging through scattering media.This advancement offers a superior solution for high-speed,high-resolution complex-field imaging beyond the visible spectrum,significantly enhancing SPI performance across various applications.展开更多
The advent of high-resolution black hole imaging—most notably by the Event Horizon Telescope(EHT)—has propelled black hole physics into a new observational regime[1].However,most theoretical interpretations remain a...The advent of high-resolution black hole imaging—most notably by the Event Horizon Telescope(EHT)—has propelled black hole physics into a new observational regime[1].However,most theoretical interpretations remain anchored in stationary,time-averaged general relativistic magnetohydrodynamic(GRMHD)simulations within the Kerr paradigm,often neglecting dynamic accretion structures and potential deviations from general relativity[2].展开更多
For practical applications of X-ray ghost imaging(XGI),the imaging time is a major challenge.In this paper,we propose a fast XGI scheme based on a continuous translation mask with etched aggregate patterns.High contra...For practical applications of X-ray ghost imaging(XGI),the imaging time is a major challenge.In this paper,we propose a fast XGI scheme based on a continuous translation mask with etched aggregate patterns.High contrastto-noise ratio images are obtained with an exposure time of only 4 s and 24 s for a 3.4 mm×3.8 mm and 5.9 mm×6.1 mm field-of-view,respectively.The spatial resolution can reach∼150μm.The influences of the sampling frequency,the mask scanning speed,and the detector integration time on image quality are examined,from which we demonstrate that the imaging time can be further reduced by increasing the mask translation speed.By applying a compressed sensing reconstruction algorithm,the exposure time is greatly reduced while maintaining image quality.Our method indicates a path for the development of future XGI applications.展开更多
Terahertz(THz)microscopy has attracted attention owing to distinctive characteristics of the THz frequency region,particularly non-ionizing photon energy,spectral fingerprint,and transparency to most nonpolar material...Terahertz(THz)microscopy has attracted attention owing to distinctive characteristics of the THz frequency region,particularly non-ionizing photon energy,spectral fingerprint,and transparency to most nonpolar materials.Nevertheless,the well-known Rayleigh diffraction limit imposed on THz waves commonly constrains the resultant imaging resolution to values beyond the millimeter scale,consequently limiting the applicability in numerous emerging applications for chemical sensing and complex media imaging.In this theoretical and numerical work,we address this challenge by introducing,to our knowledge,a new imaging approach based on acquiring high-spatial frequencies by adapting the Fourier synthetic aperture approach to the THz spectral range,thus surpassing the diffractionlimited resolution.Our methodology combines multi-angle THz pulsed illumination with time-resolved field measurements,as enabled by the state-of-the-art time-domain spectroscopy technique.We demonstrate the potential of the approach for hyperspectral THz imaging of semi-transparent samples and show that the technique can reconstruct spatial and temporal features of complex inhomogeneous samples with subwavelength resolution.展开更多
Time-resolved volumetric fluorescence imaging over an extended duration with high spatial/temporal resolution is a key driving force in biomedical research for investigating spatial-temporal dynamics at organism-level...Time-resolved volumetric fluorescence imaging over an extended duration with high spatial/temporal resolution is a key driving force in biomedical research for investigating spatial-temporal dynamics at organism-level systems,yet it remains a major challenge due to the trade-off among imaging speed,light exposure,illumination power,and image quality.Here,we present a deep-learning enhanced light sheet fluorescence microscopy(LSFM)approach that addresses the restoration of rapid volumetric time-lapse imaging with less than 0.03%light exposure and 3.3%acquisition time compared to a typical standard acquisition.We demonstrate that the convolutional neural network(CNN)-transformer network developed here,namely U-net integrated transformer(UI-Trans),successfully achieves the mitigation of complex noise-scattering-coupled degradation and outperforms state-of-the-art deep learning networks,due to its capability of faithfully learning fine details while comprehending complex global features.With the fast generation of appropriate training data via flexible switching between confocal line-scanning LSFM(LS-LSFM)and conventional LSFM,this method achieves a three-to five-fold signal-to-noise ratio(SNR)improvement and~1.8 times contrast improvement in ex vivo zebrafish heart imaging and long-term in vivo 4D(3D morphology+time)imaging of heartbeat dynamics at different developmental stages with ultra-economical acquisitions in terms of light dosage and acquisition time.展开更多
基金Under the auspices of China Postdoctoral Science Foundation (No. 20080430586, 20070420018)National Natural Science Foundation of China (No. 40801161, 40801172)Sino US International Cooperation in Science and Technology (No. 2007DFA20640)
文摘Using three-phase remote sensing images of China-Brazil Earth Resources Satellite 02B (CBERS02B) and Landsat-5 TM, tobacco field was extracted by the analysis of time series image based on the different phenological characteristics between tobacco and other crops. The spectral characteristics of tobacco and corn in luxuriant growth stage are very similar, which makes them difficult to be distinguished using a single-phase remote sensing image. Field film after tobacco seedlings transplanting can be used as significant sign to identify tobacco. Remote sensing interpre- tation map based on the fusion image of TM and CBERS02B's High-Resolution (HR) camera image was used as stan- dard reference material to evaluate the classification accuracy of Spectral Angle Mapper (SAM) and Maximum Like- lihood Classifier (MLC) for time series image based on full samples test method. SAM has higher classification accu- racy and stability than MLC in dealing with time series image. The accuracy and Kappa of tobacco coverage extracted by SAM are 83.4% and 0.692 respectively, which can achieve the accuracy required by tobacco coverage measurement in a large area.
基金funded jointly by the "Hundred Talents" Project of Chinese Academy of Sciences (CAS)the Hundred Talent Program of Sichuan Province, International Cooperation Partner Program of Innovative Team, CAS (Grant No. KZZD-EW-TZ-06)+1 种基金the Knowledge Innovation Program of the Chinese Academy of Sciences (Grant No. KZCX2-YW-QN313)the Strategic Priority Research Program-Climate Change: Carbon Budget and Related Issues (Grant No. XDA05050105)
文摘How to deal with geometric distortion is an open problem when using the massive amount of satellite images at a national or global scale, especially for multi-temporal image analysis. In this paper, an algorithm is proposed to automatically rectify the geometric distortion of time-series CCD multi- spectral data of small constellation for environmental and disaster mitigation （HJ-1A/B） which was launched by China in 2008. In this algorithm, the area-based matching method was used to automatically search tie points firstly, and then the polynomial function was introduced to correct the systematic errors caused by the satellite motion along the roll, pitch and yaw direction. The improved orthorectification method was finally used to correct pixel displacement caused by off-nadir viewing of topography, which are random errors in the images and cannot be corrected by the polynomial equation. Nine scenes of level 2 HJ CCD images from one path/row were taken as the warp images to test the algorithm. The test result showed that the overall accuracy of the proposed algorithm was within 2 pixels （the average residuals were 37.8 m, and standard deviations were 19.8 m）. The accuracies of 45.96% validation points （VPs） were within 1 pixel and 90.33% VPs were within 2 pixels. The discussion showed that three main factors including the distortion patterns of HJ CCD images, pereent of cloud cover and the varying altitude of the satellite orbit may affect the search of tie points and the accuracy of results. Although the influence of varying altitude of the satellite orbits is less than the other factors, it is noted that detailed satellite altitude information should be given in the future to get a more precise result. The proposed algorithm should be an efficient tool for the geo-correction of HJ CCD multi-spectral images.
文摘In the process of image transmission, the famous JPEG and JPEG-2000 compression methods need more transmission time as it is difficult for them to compress the image with a low compression rate. Recently the compressed sensing（CS） theory was proposed, which has earned great concern as it can compress an image with a low compression rate, meanwhile the original image can be perfectly reconstructed from only a few compressed data. The CS theory is used to transmit the high resolution astronomical image and build the simulation environment where there is communication between the satellite and the Earth. Number experimental results show that the CS theory can effectively reduce the image transmission and reconstruction time. Even with a very low compression rate, it still can recover a higher quality astronomical image than JPEG and JPEG-2000 compression methods.
基金supported partially by grants from the National Natural Science Foundation of China(82470068,82270086,GS Zhang82372185,BP Tian)+2 种基金the Natural Science Foundation of Zhejiang Province(Key Project)(LZ25H150001,GS Zhang)the National Health Commission Scientifi c Research Fund Zhejiang Provincial Health Major Science and Technology Plan Project(co-construction project of National Health Commission Committee and Zhejiang Province)(WKJ-ZJ-2526,GS Zhang)the Medical and Health Research Program of Zhejiang Province(2023572679).
文摘Electrical impedance tomography(EIT)is a non-invasive imaging modality that generates real-time images by measuring tissue bioimpedance.It works by applying current and collecting voltage data to reconstruct images of electrical conductivity,refl ecting tissue properties.[1]We aim to off er a comprehensive guide to the fundamental technology behind EIT and to explore its clinical applications across both pulmonary and extrapulmonary domains.
基金Japan International Cooperation Agency(JICA)via Malaysia-Japan Linkage Research Grant 2024.
文摘Although the image dehazing problem has received considerable attention over recent years,the existing models often prioritise performance at the expense of complexity,making them unsuitable for real-world applications,which require algorithms to be deployed on resource constrained-devices.To address this challenge,we propose WaveLiteDehaze-Network(WLD-Net),an end-to-end dehazing model that delivers performance comparable to complex models while operating in real time and using significantly fewer parameters.This approach capitalises on the insight that haze predominantly affects low-frequency infor-mation.By exclusively processing the image in the frequency domain using discrete wavelet transform(DWT),we segregate the image into high and low frequencies and process them separately.This allows us to preserve high-frequency details and recover low-frequency components affected by haze,distinguishing our method from existing approaches that use spatial domain processing as the backbone,with DWT serving as an auxiliary component.DWT is applied at multiple levels for better in-formation retention while also accelerating computation by downsampling feature maps.Subsequently,a learning-based fusion mechanism reintegrates the processed frequencies to reconstruct the dehazed image.Experiments show that WLD-Net out-performs other low-parameter models on real-world hazy images and rivals much larger models,achieving the highest PSNR and SSIM scores on the O-Haze dataset.Qualitatively,the proposed method demonstrates its effectiveness in handling a diverse range of haze types,delivering visually pleasing results and robust performance,while also generalising well across different scenarios.With only 0.385 million parameters(more than 100 times smaller than comparable dehazing methods),WLD-Net processes 1024×1024 images in just 0.045 s,highlighting its applicability across various real-world scenarios.The code is available at https://github.com/AliMurtaza29/WLD-Net.
基金funding via EUROfusion Enabling research Project No.AWP21-ENR-01-CEA-02“Advancing Shock Ignition for Direct-Drive Inertial Fusion,”the framework of the EUROfusion Consortium,funded by the European Union via the Euratom Research and Training Programme (Grant Agreement No.101052200-EUROfusion)+2 种基金the Czech Ministry of Education,Youth and Sports (CMEYS) for funding the operation of the PALS facility (Grant No.LM2023068)the EuroHPC Joint Undertaking for awarding access to Karolina at IT4Innovations (VSB-TU),Czechia under Project No.EHPC-REG-2023R02-006(DD-23-157)the Ministry of Education,Youth and Sports of the Czech Republic through e-INFRA CZ (Grant No.ID:90140)
文摘We investigate the spatial and temporal correlations of hot-electron generation in high-intensity laser interaction with massive and thin copper targets under conditions relevant to inertial confinement fusion.Using Ka time-resolved imaging,it is found that in the case of massive targets,the hot-electron generation follows the laser pulse intensity with a short delay needed for favorable plasma formation.Conversely,a significant delay in the x-ray emission compared with the laser pulse intensity profile is observed in the case of thin targets.Theoretical analysis and numerical simulations suggest that this is related to radiation preheating of the foil and the increase in hot-electron lifetime in a hot expanding plasma.
基金supported by the Innovation Foundation for Scientific Research Base(NJ20140008NJ20150018)+1 种基金the Aeronautical Science Foundation of China(20132052035)the National Defense Basic Scientific Research(B2520110008)
文摘The optimal imaging time selection of ship targets for shore-based inverse synthetic aperture radar （ISAR） in high sea conditions is investigated. The optimal imaging time includes opti- mal imaging instants and optimal imaging duration. A novel method for optimal imaging instants selection based on the estimation of the Doppler centroid frequencies （DCFs） of a series of images obtained over continuous short durations is proposed. Combined with the optimal imaging duration selection scheme using the image contrast maximization criteria, this method can provide the ship images with the highest focus. Simulated and real data pro- cessing results verify the effectiveness of the proposed imaging method.
文摘Electrical capacitance volume tomography(ECVT) is a recently-developed technique for real-time,non-invasive 3D monitoring of processes involving materials with strong contrasts in dielectric permittivity.This work is first application of the method to visualization of water flow in soil.We describe the principles behind the method,and then demonstrate its use with a simple laboratory infiltration experiment.32 ECVT sensors were installed on the sides of an empty PVC column.Water was poured into the column at a constant rate,and ECVT data were collected every second.The column was then packed with dry sand and again supplied with water at a constant rate with data collected every second.Data were analyzed to give bulk average water contents,which proved consistent with the water supply rates.Data were also analyzed to give 3D images(216 voxels) allowing visualization of the water distribution during the experiments.Result of this work shows that water infiltration into the soil,wall flow,progress of the unstable wetting front and the final water distribution are clearly visible.
基金We acknowledge the support of the Australian Research Council for the Center of Excellence for Coherent X-ray Science(CE0561787).
文摘A wide range of techniques has been developed to image biological samples at high spatial and temporal resolution.In this paper,we report recent results from deep-UV confocal fAuorescence microscopy to image inherent emission from fuorophores such as tryptophan,and structured ilumination microscopy(SIM)of biological materials.One motivation for developing deep-UV fhuorescence imaging and SIM is to provide methods to complement our measurements in the emerging field of X-ray coherent diffractive imaging.
文摘In our previous work, a novel algorithm to perform robust pose estimation was presented. The pose was estimated using points on the object to regions on image correspondence. The laboratory experiments conducted in the previous work showed that the accuracy of the estimated pose was over 99% for position and 84% for orientation estimations respectively. However, for larger objects, the algorithm requires a high number of points to achieve the same accuracy. The requirement of higher number of points makes the algorithm, computationally intensive resulting in the algorithm infeasible for real-time computer vision applications. In this paper, the algorithm is parallelized to run on NVIDIA GPUs. The results indicate that even for objects having more than 2000 points, the algorithm can estimate the pose in real time for each frame of high-resolution videos.
基金supported by the National Natural Science Fundation of China(Grant Nos.1110510611375144&11275153)
文摘Recently, Sandia Laboratories developed a neutron scatter camera to detect special nuclear materials. This camera exhibits the following advantages: high efficiency, direction discrimination, neutron-gamma discrimination ability, and wide field of view. However, using the direct projection method, the angular resolution of this camera is limited by uncertainties in the energies estimated from pulse height and time of flight measurements. In this study, we established an eight-element neutron scatter camera and conducted the experiment with a ^(252)Cf neutron source. The results show that it has an angular resolution better than 8°(1s) and a detection efficiency of approximately 2.6′10-4. Using maximum likelihood expectation maximization method, the image artifact was eliminated, and the angular resolution was improved. We proposed an average scattering angle method to estimate the scattering energy of neutrons and Compton gamma rays. As such, we can obtain a recognizable image and energy spectrum of the source with some degradation of energy and image resolutions. Finally, a newly measured light response function based on the MPD^(-4) device was used for image reconstruction. Although we did not obtain a better result than that of the standard light response function, we have observed the effects of light response function on image reconstruction.
基金supported by National Key R&D Program of China(2023YFC2416400)Shenzhen Medical Research Fund(B2302053)+6 种基金Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0930000)National Natural Science Foundation of China Grants of China(12274430,82327805,12304516,12174267,and 12204504)Shenzhen Foundation Grant(GJHZ20220913142810021,KCXFZ20230731093959009,JSGGZD20220822095602005,and ZDSYS201802061806314)CAS research projects(KFJ-PTXM-012)Natural Science Foundation of Guangdong Province(2024B1212010010,2022A1515011343,and 2020B1212060051)Youth Innovation Promotion Association CAS 2018391the ethical guidelines of the Shenzhen Advanced Animal Study Service Center,China(AMS D2305011P).
文摘Ultrasound imaging-guided spinal puncture is highly desirable for the treat-ment of degenerative diseases of the spine,cerebrospinal fluid sampling,and spinal anesthesia administration due to its real-time and portable na-ture.However,conventional ultrasound imaging guidance methods image the target area from outside the body and obtain only two-dimensional(2D)images,making it very difficult to identify the puncture needle and under-stand the situation behind the vertebrae during the puncture process.Here,we present a new method for placing a 2D ultrasound array trans-ducer into the needle tip.The array has a stepped shape that fits well with the puncture needle,and real-time three-dimensional(3D)volumetric images can be obtained in the body in front of the needle as guidance dur-ing the puncture procedure.Our innovative transducer design and fabrica-tion method enable the integration of a 10-MHz,256-element 2D array transducer in the needle tip,leading to superior imaging resolution.The re-sults of in vitro and in vivo pig experiments demonstrate that the needle po-sition can be clearly identified and guided during the puncture process.This technology can improve the guidance accuracy and greatly reduce un-expected risks during puncture procedures,which has great potential in spinal punctures in clinical settings.
基金supported by the National Key R&D Program of China(2023YFF0723300)National Natural Science Foundation of China(62475198,62075200,12374295)+8 种基金Fundamental Research Funds for the Central Universities(2042024kf0003,2042024kf1010,2042023kf0105)Hubei Provincial Natural Science Foundation of China(2023AFB133)Jiangsu Science and Technology Program(BK20221257)Shenzhen Science and Technology Program(JCYJ20220530140601003,JCYJ20230807090207014)Translational Medicine and Multidisciplinary Research Project of Zhongnan Hospital of Wuhan University(ZNJC202217,ZNJC202232)The Interdisciplinary Innovative Talents Foundation from Renmin Hospital of Wuhan University(JCRCYR-2022-006)Hubei Province Young Science and Technology Talent Morning Hight Lift Project(202319)The Fund of National Key Laboratory of Plasma Physics(6142A04230201)We gratefully acknowledge Serendipity Lab for facilitating collaboration opportunities.
文摘Imaging flow cytometry(IFC)combines the imaging capabilities of microscopy with the high throughput of flow cytometry,offering a promising solution for high-precision and high-throughput cell analysis in fields such as biomedicine,green energy,and environmental monitoring.However,due to limitations in imaging framerate and realtime data processing,the real-time throughput of existing IFC systems has been restricted to approximately 1000-10,000 events per second(eps),which is insufficient for large-scale cell analysis.In this work,we demonstrate IFC with real-time throughput exceeding 1,000,000 eps by integrating optical time-stretch(OTS)imaging,microfluidic-based cell manipulation,and online image processing.Cells flowing at speeds up to 15 m/s are clearly imaged with a spatial resolution of 780 nm,and images of each individual cell are captured,stored,and analyzed.The capabilities and performance of our system are validated through the identification of malignancies in clinical colorectal samples.This work sets a new record for throughput in imaging flow cytometry,and we believe it has the potential to revolutionize cell analysis by enabling highly efficient,accurate,and intelligent measurement.
基金support of CONAHCYT(Consejo Nacional de Humanidades,Ciencias y Tecnologías,México)in the form of Graduate Program Scholarships and the support by Tecnológico de Monterrey in the form of tuition fee waiverthe funding provided by CONAHCYT in the form of scholarship as member of the National System of Researchers(SNI 1047863)+2 种基金he financial support of Federico Baur Endowed Chair in Nanotechnology(ILST002-23ID69001)the funding provided by CONAHCYT in the form of scholarship as a member of the National System of Researchers(CVU:969467)the financial support of FEMSA foundation.
文摘Biopolymer core-shell microspheres play a crucial role in various biomedical applications,including drug delivery,tissue engineering,and diagnostics.These applications require microparticles with consistent,well-controlled size and precise shape fidelity.However,achieving high-throughput synthesis of size and shape-controlled core-shell biopolymer microgels remains a significant challenge.Herein,we present a one-step process for the high-throughput generation of monodisperse,luminescent,chitosan alginate core-shell microspheres by a novel manipulation of a centrifugal microfluidic device.We utilized the pH sensitivity of chitosan and the ionic gelation properties of alginate to create well-defined core-shell morphologies.To address particle merging issues and promote uniform particle size generation,we introduced an innovative pulsed mode operation in our centrifugal microfluidics device.We also incorporated fluorescent,nitrogen-functionalized graphene quantum dots into the core-shell structures,thereby rendering them useful for real-time imaging,which is necessary for diagnostic and therapeutic applications.To enhance biocompatibility,the alginate solution was supplemented with fish gelatin(FG).The resulting microspheres exhibited excellent structural integrity maintaining their core-shell structure after 15 days.Biocompatibility was demonstrated by C2C12 cell viability exceeding 88%after 15 days and by bacterial viability reaching the same percentage after 2 days.The system demonstrates considerable scalability,allowing for the consistent production of large quantities of microspheres without compromising functionality.The streamlined and efficient methodology simplifies the production process while unlocking new possibilities in targeted therapies,tissue regeneration,and diagnostics.
基金supported in part by the National Natural Science Foundation of China(12404380,12325408,12274129,12374274,12274139,62175069,62175066,62475070,12474404)the Fundamental and Applied Basic Research Project of Guangzhou(2024A04J2001)+2 种基金the Guangdong Basic and Applied Basic Research Foundation(2023A1515110742,2023B1515120044,2024B1515020051)Shanghai Municipal Education Commission(2024AI01007)Science and Technology Commission of Shanghai Municipality(QNKJ2024031).
文摘Single-pixel imaging(SPI)is a promising technology for optical imaging beyond the visible spectrum,where commercial cameras are expensive or unavailable.However,limitations such as slow pattern projection rates and time-consuming reconstruction algorithms hinder its throughput for real-time imaging.Consequently,conventional SPI is inadequate for high-speed,high-resolution tasks.To address these challenges,we developed an ultrahigh-throughput single-pixel complex-field microscopy(SPCM)system utilizing frequency-comb acousto-optic coherent encoding(FACE).This system enables real-time complex-field monitoring in the non-visible domain.Operating at 1030 nm,our system achieves a record-high space-bandwidth-time product(SBP-T)of 1.3×10^(7),surpassing previous SPCM(~10^(4)),SPI(~10^(5)),and even certain types of commercial near-infrared cameras(~10^(6)).It supports real-time streaming at 1000 Hz with a frame size of 80×81 pixels and a lateral resolution of 3.76μm across an approximately 300μm field of view.We validated the system by imaging dynamic transparent scenes,including microfluidics,live microorganisms,chemical reactions,as well as imaging through scattering media.This advancement offers a superior solution for high-speed,high-resolution complex-field imaging beyond the visible spectrum,significantly enhancing SPI performance across various applications.
文摘The advent of high-resolution black hole imaging—most notably by the Event Horizon Telescope(EHT)—has propelled black hole physics into a new observational regime[1].However,most theoretical interpretations remain anchored in stationary,time-averaged general relativistic magnetohydrodynamic(GRMHD)simulations within the Kerr paradigm,often neglecting dynamic accretion structures and potential deviations from general relativity[2].
基金National Natural Science Foundation of China(61975229,12335016,11991073,W2412039,61805006)National Key R&D Program of China(2018YFB0504302)Strategic Priority Research Program of the CAS(XDA25030400,XDA25010100).
文摘For practical applications of X-ray ghost imaging(XGI),the imaging time is a major challenge.In this paper,we propose a fast XGI scheme based on a continuous translation mask with etched aggregate patterns.High contrastto-noise ratio images are obtained with an exposure time of only 4 s and 24 s for a 3.4 mm×3.8 mm and 5.9 mm×6.1 mm field-of-view,respectively.The spatial resolution can reach∼150μm.The influences of the sampling frequency,the mask scanning speed,and the detector integration time on image quality are examined,from which we demonstrate that the imaging time can be further reduced by increasing the mask translation speed.By applying a compressed sensing reconstruction algorithm,the exposure time is greatly reduced while maintaining image quality.Our method indicates a path for the development of future XGI applications.
基金Agence Nationale de la Recherche(ANR-22-CE42-0005-HYPSTER,ANR 22-PEEL-0003-Comptera)。
文摘Terahertz(THz)microscopy has attracted attention owing to distinctive characteristics of the THz frequency region,particularly non-ionizing photon energy,spectral fingerprint,and transparency to most nonpolar materials.Nevertheless,the well-known Rayleigh diffraction limit imposed on THz waves commonly constrains the resultant imaging resolution to values beyond the millimeter scale,consequently limiting the applicability in numerous emerging applications for chemical sensing and complex media imaging.In this theoretical and numerical work,we address this challenge by introducing,to our knowledge,a new imaging approach based on acquiring high-spatial frequencies by adapting the Fourier synthetic aperture approach to the THz spectral range,thus surpassing the diffractionlimited resolution.Our methodology combines multi-angle THz pulsed illumination with time-resolved field measurements,as enabled by the state-of-the-art time-domain spectroscopy technique.We demonstrate the potential of the approach for hyperspectral THz imaging of semi-transparent samples and show that the technique can reconstruct spatial and temporal features of complex inhomogeneous samples with subwavelength resolution.
基金supported by National Natural Science Foundation of China(52122008,52270008,52370003,62025502)Guangdong Introducing Innovative and Entrepreneurial Teams of“The Pearl River Talent Recruitment Program”(2021ZT09X044)Shenzhen Technology University under Grant JSZZ202301010.
文摘Time-resolved volumetric fluorescence imaging over an extended duration with high spatial/temporal resolution is a key driving force in biomedical research for investigating spatial-temporal dynamics at organism-level systems,yet it remains a major challenge due to the trade-off among imaging speed,light exposure,illumination power,and image quality.Here,we present a deep-learning enhanced light sheet fluorescence microscopy(LSFM)approach that addresses the restoration of rapid volumetric time-lapse imaging with less than 0.03%light exposure and 3.3%acquisition time compared to a typical standard acquisition.We demonstrate that the convolutional neural network(CNN)-transformer network developed here,namely U-net integrated transformer(UI-Trans),successfully achieves the mitigation of complex noise-scattering-coupled degradation and outperforms state-of-the-art deep learning networks,due to its capability of faithfully learning fine details while comprehending complex global features.With the fast generation of appropriate training data via flexible switching between confocal line-scanning LSFM(LS-LSFM)and conventional LSFM,this method achieves a three-to five-fold signal-to-noise ratio(SNR)improvement and~1.8 times contrast improvement in ex vivo zebrafish heart imaging and long-term in vivo 4D(3D morphology+time)imaging of heartbeat dynamics at different developmental stages with ultra-economical acquisitions in terms of light dosage and acquisition time.
