Color Fourier single-pixel imaging(FSI)enables efficient spectral and spatial imaging.Here,we propose a Fourier single-pixel imaging scheme with a random color filter array(FSI-RCFA).The proposed method employs a rand...Color Fourier single-pixel imaging(FSI)enables efficient spectral and spatial imaging.Here,we propose a Fourier single-pixel imaging scheme with a random color filter array(FSI-RCFA).The proposed method employs a random color filter array(RCFA)to modulate Fourier patterns.A three-step phase-shifting technique reconstructs the Fourier spectrum,followed by an RCFA-based demosaicing algorithm to recover color images.Compared to traditional color FSI based on Bayer color filter array schemes(FSI-BCFA),our approach achieves superior separation between chrominance and luminance components in the frequency domain.Simulation results demonstrate that the FSI-RCFA method achieves a lower mean squared error(MSE),a higher peak signal-to-noise ratio(PSNR),and superior noise resistance compared to FSI-BCFA,while enabling direct single-channel pixel measurements for targeted applications such as agricultural defect detection.展开更多
Single-pixel imaging(SPI)enables efficient sensing in challenging conditions.However,the requirement for numerous samplings constrains its practicality.We address the challenge of high-quality SPI reconstruction at ul...Single-pixel imaging(SPI)enables efficient sensing in challenging conditions.However,the requirement for numerous samplings constrains its practicality.We address the challenge of high-quality SPI reconstruction at ultra-low sampling rates.We develop an alternative optimization with physics and a data-driven diffusion network(APD-Net).It features alternative optimization driven by the learned task-agnostic natural image prior and the task-specific physics prior.During the training stage,APD-Net harnesses the power of diffusion models to capture data-driven statistics of natural signals.In the inference stage,the physics prior is introduced as corrective guidance to ensure consistency between the physics imaging model and the natural image probability distribution.Through alternative optimization,APD-Net reconstructs data-efficient,high-fidelity images that are statistically and physically compliant.To accelerate reconstruction,initializing images with the inverse SPI physical model reduces the need for reconstruction inference from 100 to 30 steps.Through both numerical simulations and real prototype experiments,APD-Net achieves high-quality,full-color reconstructions of complex natural images at a low sampling rate of 1%.In addition,APD-Net’s tuning-free nature ensures robustness across various imaging setups and sampling rates.Our research offers a broadly applicable approach for various applications,including but not limited to medical imaging and industrial inspection.展开更多
Existing single-pixel imaging(SPI)and sensing techniques suffer from poor reconstruction quality and heavy computation cost,limiting their widespread application.To tackle these challenges,we propose a large-scale sin...Existing single-pixel imaging(SPI)and sensing techniques suffer from poor reconstruction quality and heavy computation cost,limiting their widespread application.To tackle these challenges,we propose a large-scale single-pixel imaging and sensing(SPIS)technique that enables high-quality megapixel SPI and highly efficient image-free sensing with a low sampling rate.Specifically,we first scan and sample the entire scene using small-size optimized patterns to obtain information-coupled measurements.Compared with the conventional full-sized patterns,small-sized optimized patterns achieve higher imaging fidelity and sensing accuracy with 1 order of magnitude fewer pattern parameters.Next,the coupled measurements are processed through a transformer-based encoder to extract high-dimensional features,followed by a task-specific plugand-play decoder for imaging or image-free sensing.Considering that the regions with rich textures and edges are more difficult to reconstruct,we use an uncertainty-driven self-adaptive loss function to reinforce the network’s attention to these regions,thereby improving the imaging and sensing performance.Extensive experiments demonstrate that the reported technique achieves 24.13 dB megapixel SPI at a sampling rate of 3%within 1 s.In terms of sensing,it outperforms existing methods by 12%on image-free segmentation accuracy and achieves state-of-the-art image-free object detection accuracy with an order of magnitude less data bandwidth.展开更多
Neutron-induced gamma-ray imaging is a spectroscopic technique that uses characteristic gamma rays to infer the elemental distribution of an object.Currently,this technique requires the use of large facilities to supp...Neutron-induced gamma-ray imaging is a spectroscopic technique that uses characteristic gamma rays to infer the elemental distribution of an object.Currently,this technique requires the use of large facilities to supply a high neutron flux and a time-consuming detection procedure involving direct collimating measurements.In this study,a new method based on low neutron flux was proposed.A single-pixel gamma-ray detector combined with random pattern gamma-ray masks was used to measure the characteristic gamma rays emitted from the sample.Images of the elemental distribution in the sample,comprising 30×30 pixels,were reconstructed using the maximum-likelihood expectation-maximization algorithm.The results demonstrate that the elemental imaging of the sample can be accurately determined using this method.The proposed approach,which eliminates the need for high neutron flux and scanning measurements,can be used for in-field imaging applications.展开更多
We propose pattern self-referenced single-pixel common-path holography(PSSCH),which can be realized using either the digital-micromirror-device(DMD)based off-axis scheme or the DMD-based phaseshifting approach,sharing...We propose pattern self-referenced single-pixel common-path holography(PSSCH),which can be realized using either the digital-micromirror-device(DMD)based off-axis scheme or the DMD-based phaseshifting approach,sharing the same experimental setup,to do wavefront reconstructions.In this method,each modulation pattern is elaborately encoded to be utilized to not only sample the target wavefront but also to dynamically introduce the reference light for single-pixel common-path holographic detection.As such,it does not need to intentionally introduce a static reference light,resulting in it making full use of the pixel resolution of the modulation patterns and suppressing dynamically varying noises.Experimental demonstrations show that the proposed method can not only obtain a larger field of view than the peripheral-referenced approach but also achieve a higher imaging resolution than the checkerboardreferenced approach.The phase-shifting-based PSSCH performs better than the off-axis-based PSSCH on imaging fidelity,while the imaging speed of the latter is several times faster.Further,we demonstrate our method to do wavefront imaging of a biological sample as well as to do phase detection of a physical lens.The experimental results suggest its effectiveness in applications.展开更多
Single-pixel imaging(SPI)can transform 2D or 3D image data into 1D light signals,which offers promising prospects for image compression and transmission.However,during data communication these light signals in public ...Single-pixel imaging(SPI)can transform 2D or 3D image data into 1D light signals,which offers promising prospects for image compression and transmission.However,during data communication these light signals in public channels will easily draw the attention of eavesdroppers.Here,we introduce an efficient encryption method for SPI data transmission that uses the 3D Arnold transformation to directly disrupt 1D single-pixel light signals and utilizes the elliptic curve encryption algorithm for key transmission.This encryption scheme immediately employs Hadamard patterns to illuminate the scene and then utilizes the 3D Arnold transformation to permutate the 1D light signal of single-pixel detection.Then the transformation parameters serve as the secret key,while the security of key exchange is guaranteed by an elliptic curve-based key exchange mechanism.Compared with existing encryption schemes,both computer simulations and optical experiments have been conducted to demonstrate that the proposed technique not only enhances the security of encryption but also eliminates the need for complicated pattern scrambling rules.Additionally,this approach solves the problem of secure key transmission,thus ensuring the security of information and the quality of the decrypted images.展开更多
The single-pixel imaging(SPI) technique is able to capture two-dimensional(2 D) images without conventional array sensors by using a photodiode. As a novel scheme, Fourier single-pixel imaging(FSI) has been proven cap...The single-pixel imaging(SPI) technique is able to capture two-dimensional(2 D) images without conventional array sensors by using a photodiode. As a novel scheme, Fourier single-pixel imaging(FSI) has been proven capable of reconstructing high-quality images. Due to the fact that the Fourier basis patterns(also known as grayscale sinusoidal patterns)cannot be well displayed on the digital micromirror device(DMD), a fast FSI system is proposed to solve this problem by binarizing Fourier pattern through a dithering algorithm. However, the traditional dithering algorithm leads to low quality as the extra noise is inevitably induced in the reconstructed images. In this paper, we report a better dithering algorithm to binarize Fourier pattern, which utilizes the Sierra–Lite kernel function by a serpentine scanning method. Numerical simulation and experiment demonstrate that the proposed algorithm is able to achieve higher quality under different sampling ratios.展开更多
We present an optical encryption method of multiple three-dimensional objects based on multiple interferences and single-pixel digital holography. By modifying the Mach-Zehnder interferometer, the interference of the ...We present an optical encryption method of multiple three-dimensional objects based on multiple interferences and single-pixel digital holography. By modifying the Mach-Zehnder interferometer, the interference of the multiple objects beams and the one reference beam is used to simultaneously encrypt multiple objects into a ciphertext. During decryption, each three-dimensional object can be decrypted independently without having to decrypt other objects. Since the single- pixel digital holography based on compressive sensing theory is introduced, the encrypted data of this method is effectively reduced. In addition, recording fewer encrypted data can greatly reduce the bandwidth of network transmission. Moreover, the compressive sensing essentially serves as a secret key that makes an intruder attack invalid, which means that the system is more secure than the conventional encryption method. Simulation results demonstrate the feasibility of the proposed method and show that the system has good security performance.展开更多
Large field-of-view（FoV） three-dimensional（3 D） photon-counting imaging is demonstrated with a single-pixel single-photon detector based on a Geiger-mode Si-avalanche photodiode. By removing the collecting lens（C...Large field-of-view（FoV） three-dimensional（3 D） photon-counting imaging is demonstrated with a single-pixel single-photon detector based on a Geiger-mode Si-avalanche photodiode. By removing the collecting lens（CL）before the detector, the FoV is expanded to ±10°. Thanks to the high detection efficiency, the signal-to-noise ratio of the imaging system is as high as 7.8 dB even without the CL when the average output laser pulse energy is about 0.45 pJ/pulse for imaging the targets at a distance of 5 m. A 3 D image overlaid with the reflectivity data is obtained according to the photon-counting time-of-flight measurement and the return photon intensity.展开更多
We propose a method of complex-amplitude Fourier single-pixel imaging(CFSI)with coherent structured illumination to acquire both the amplitude and phase of an object.In the proposed method,an object is illustrated by ...We propose a method of complex-amplitude Fourier single-pixel imaging(CFSI)with coherent structured illumination to acquire both the amplitude and phase of an object.In the proposed method,an object is illustrated by a series of coherent structured light fields,which are generated by a phase-only spatial light modulator,the complex Fourier spectrum of the object can be acquired sequentially by a single-pixel photodetector.Then the desired complex-amplitude image can be retrieved directly by applying an inverse Fourier transform.We experimentally implemented this CFSI with several different types of objects.The experimental results show that the proposed method provides a promising complex-amplitude imaging approach with high quality and a stable configuration.Thus,it might find broad applications in optical metrology and biomedical science.展开更多
We propose a single-pixel imaging(SPI)method to achieve a higher-resolution image via the Hadamard transform matrix.Unlike traditional SPI schemes,this new method recovers images by correlating single-pixel signals wi...We propose a single-pixel imaging(SPI)method to achieve a higher-resolution image via the Hadamard transform matrix.Unlike traditional SPI schemes,this new method recovers images by correlating single-pixel signals with synchronized transformed patterns of Hadamard bases that are actually projected onto the digital micromirror device.Each transform pattern is obtained through the inverse Fourier transform of the pattern acquired by Gaussian filtering of each Hadamard basis in the frequency domain.The proposed scheme is based on a typical SPI experimental setup and does not add any hardware complexity,enabling the transformation of Hadamard matrices and image reconstruction through data processing alone.Therefore,this approach could be considered as an alternative option for achieving fast SPI in a diffraction-limited imaging system,without the need for additional hardware.展开更多
A traditional single-pixel camera needs a large number of measurements to reconstruct the object with compressive sensing computation.Compared with the 1/0 matrices in classical measurement,the 1/-1 matrices in the co...A traditional single-pixel camera needs a large number of measurements to reconstruct the object with compressive sensing computation.Compared with the 1/0 matrices in classical measurement,the 1/-1 matrices in the complementary measurement has better property for reconstruction computation and returns better reconstruction results.However,each row of the 1/-1 matrices needs two measurements with the traditional single-pixel camera which results into double measurements compared with the 1/0 matrices.In this paper,we consider the pseudo complementary measurement which only takes the same amount of measurements with the row number of some properly designed 1/0 matrix to compute the total luminous flux of the objective and derives the measurement data of the corresponding 1/-1 matrix in a mathematical way.The numerical simulation and experimental result show that the pseudo complementary measurement is an efficient tool for the traditional single-pixel camera imaging under low measurement rate,which can combine the advantages of the classical and complementary measurements and significantly improve the peak signal-to-noise ratio.展开更多
Photon-level single-pixel imaging overcomes the reliance of traditional imaging techniques on large-scale array detectors,offering the advantages such as high sensitivity,high resolution,and efficient photon utilizati...Photon-level single-pixel imaging overcomes the reliance of traditional imaging techniques on large-scale array detectors,offering the advantages such as high sensitivity,high resolution,and efficient photon utilization.In this paper,we propose a photon-level dynamic feature single-pixel imaging method,leveraging the frequency domain sparsity of the object's dynamic features to construct a compressed measurement system through discrete random photon detection.In the experiments,we successfully captured 167 and 200 Hz featured frequencies and achieved high-quality image reconstruction with a data compression ratio of 20%.Our approach introduces a new detection dimension,significantly expanding the applications of photon-level single-pixel imaging in practical scenarios.展开更多
Cross-species pose estimation plays a vital role in studying neural mechanisms and behavioral patterns while serving as a fundamental tool for behavior monitoring and prediction.However,conventional image-based approa...Cross-species pose estimation plays a vital role in studying neural mechanisms and behavioral patterns while serving as a fundamental tool for behavior monitoring and prediction.However,conventional image-based approaches face substantial limitations,including excessive storage requirements,high transmission bandwidth demands,and massive computational costs.To address these challenges,we introduce an image-free pose estimation framework based on single-pixel cameras operating at ultra-low sampling rates(6.260×10^(-4)).Our method eliminates the need for explicit or implicit image reconstruction,instead directly extracting pose information from highly compressed single-pixel measurements.It dramatically reduces data storage and transmission requirements while maintaining accuracy comparable to traditional image-based methods.Our solution provides a practical approach for real-world applications where bandwidths and computational resources are constrained.展开更多
Existing two-step Fourier single-pixel imaging (FSPI) suffers from low noise-robustness, and three-step FSPI and four-step FSPI improve the noise-robustness but at the cost of more measurements. In this Letter, we pro...Existing two-step Fourier single-pixel imaging (FSPI) suffers from low noise-robustness, and three-step FSPI and four-step FSPI improve the noise-robustness but at the cost of more measurements. In this Letter, we propose a method to improve the noise-robustness of two-step FSPI without additional illumination patterns or measurements. In the proposed method, the measurements from base patterns are replaced by the average values of the measurement from two sets of phase-shift patterns. Thus, the imaging degradation caused by the noise in the measurements from base patterns can be avoided, and more reliable Fourier spectral coefficients are obtained. The imaging quality of the proposed robust two-step FSPI is similar to those of three-step FSPI and four-step FSPI. Simulations and experimental results validate the effectiveness of the proposed method.展开更多
Hyperspectral-depth imaging is of great importance in many fields.However,it is difficult for most systems to achieve good spectral resolution and accurate location at the same time.Here,we present a hyperspectral-dep...Hyperspectral-depth imaging is of great importance in many fields.However,it is difficult for most systems to achieve good spectral resolution and accurate location at the same time.Here,we present a hyperspectral-depth single-pixel imaging system that exploits the two reflection beam paths of a spatial light modulator to provide one-dimensional depth and spectral information of the object;then,they are combined with the modulation patterns and compressed-sensing algorithm to construct the hyperspectral-depth image,even at a sampling ratio of 25%.In our experiments,a spectral resolution of 1.2 nm in the range of 420 to 780 nm is achieved,with a depth measurement error of less than 1 cm.Our work thus provides a new way for hyperspectral-depth imaging.展开更多
Single-pixel imaging(SPI)is a computational imaging technique that is able to reconstruct high-resolution images using a single-pixel detector.However,most SPI demonstrations have been mainly focused on macroscopic sc...Single-pixel imaging(SPI)is a computational imaging technique that is able to reconstruct high-resolution images using a single-pixel detector.However,most SPI demonstrations have been mainly focused on macroscopic scenes,so their applications to biological specimens are generally limited by constraints in space-bandwidth-time product and spatial resolution.In this work,we further enhance SPI's imaging capabilities for biological specimens by developing a high-resolution holographic system based on heterodyne holography.Our SPI system achieves a space-bandwidth-time product of 41,667 pixel/s and a lateral resolution of 4±5μm,which represent state-of-the-art technical indices among reported SPI systems.Importantly,our SPI system enables detailed amplitude imaging with high contrast for stained specimens such as epithelial and esophageal cancer samples,while providing complementary phase imaging for unstained specimens including molecular diagnostic samples and mouse brain tissue slices,revealing subtle refractive index variations.These results highlight SPI's versatility and establish its potential as a powerful tool for advanced biomedical imaging applications.展开更多
Single-pixel imaging(SPI)is a prominent scattering media imaging technique that allows image transmission via one-dimensional detection under structured illumination,with applications spanning from long-range imaging ...Single-pixel imaging(SPI)is a prominent scattering media imaging technique that allows image transmission via one-dimensional detection under structured illumination,with applications spanning from long-range imaging to microscopy.Recent advancements leveraging deep learning(DL)have significantly improved SPI performance,especially at low compression ratios.However,most DL-based SPI methods proposed so far rely heavily on extensive labeled datasets for supervised training,which are often impractical in real-world scenarios.Here,we propose an unsupervised learningenabled label-free SPI method for resilient information transmission through unknown dynamic scattering media.Additionally,we introduce a physics-informed autoencoder framework to optimize encoding schemes,further enhancing image quality at low compression ratios.Simulation and experimental results demonstrate that high-efficiency data transmission with structural similarity exceeding 0.9 is achieved through challenging turbulent channels.Moreover,experiments demonstrate that in a 5 m underwater dynamic turbulent channel,USAF target imaging quality surpasses traditional methods by over 13 dB.The compressive encoded transmission of 720×720 resolution video exceeding 30 seconds with great fidelity is also successfully demonstrated.These preliminary results suggest that our proposed method opens up a new paradigm for resilient information transmission through unknown dynamic scattering media and holds potential for broader applications within many other scattering media imaging technologies.展开更多
The demand for high-performance X-ray detectors leads to material innovationfor efficient photoelectric conversion and carrier transfer. However, currentX-ray detectors are often susceptible to chemical and irradiatio...The demand for high-performance X-ray detectors leads to material innovationfor efficient photoelectric conversion and carrier transfer. However, currentX-ray detectors are often susceptible to chemical and irradiation instability,complex fabrication processes, hazardous components, and difficult compatibility.Here, we investigate a two-dimensional (2D) material with a relativelylow atomic number, Ti_(3)C_(2)T_(x) MXenes, and single crystal silicon for X-ray detectionand single-pixel imaging (SPI). We fabricate a Ti_(3)C_(2)T_(x) MXene/Si X-raydetector demonstrating remarkable optoelectronic performance. This detectorexhibits a sensitivity of 1.2 × 10^(7) μC Gyair^(-1) cm^(-2), a fast response speed with arise time of 31 μs, and an incredibly low detection limit of 2.85 nGyair s^(-1).These superior performances are attributed to the unique charge couplingbehavior under X-ray irradiation via intrinsic polaron formation. The deviceremains stable even after 50 continuous hours of high-dose X-ray irradiation.Our device fabrication process is compatible with silicon-based semiconductortechnology. Our work suggests new directions for eco-friendly X-ray detectorsand low-radiation imaging system.展开更多
Single-pixel imaging (SPI) captures two-dimensional images utilizing a sequence of modulation patterns and measurements recorded by a single-pixel detector. However, the sequential measurement of a scene is time-consu...Single-pixel imaging (SPI) captures two-dimensional images utilizing a sequence of modulation patterns and measurements recorded by a single-pixel detector. However, the sequential measurement of a scene is time-consuming, especially for high-spatial-resolution imaging. Furthermore, for spectral SPI, the enormous data storage and processing time requirements substantially diminish imaging efficiency. To reduce the required number of patterns, we propose a strategy by optimizing a Hadamard pattern sequence via Morton frequency domain scanning to enhance the quality of a reconstructed spectral cube at low sampling rates. Additionally, we expedite spectral cube reconstruction, eliminating the necessity for a large Hadamard matrix. We demonstrate the effectiveness of our approach through both simulation and experiment,achieving sub-Nyquist sampling of a three-dimensional spectral cube with a spatial resolution of 256×256 pixels and181 spectral bands and a reduction in reconstruction time by four orders of magnitude. Consequently, our method offers an efficient solution for compressed spectral imaging.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.62001249 and62375140)。
文摘Color Fourier single-pixel imaging(FSI)enables efficient spectral and spatial imaging.Here,we propose a Fourier single-pixel imaging scheme with a random color filter array(FSI-RCFA).The proposed method employs a random color filter array(RCFA)to modulate Fourier patterns.A three-step phase-shifting technique reconstructs the Fourier spectrum,followed by an RCFA-based demosaicing algorithm to recover color images.Compared to traditional color FSI based on Bayer color filter array schemes(FSI-BCFA),our approach achieves superior separation between chrominance and luminance components in the frequency domain.Simulation results demonstrate that the FSI-RCFA method achieves a lower mean squared error(MSE),a higher peak signal-to-noise ratio(PSNR),and superior noise resistance compared to FSI-BCFA,while enabling direct single-channel pixel measurements for targeted applications such as agricultural defect detection.
基金upported by the National Natural Science Foundation of China(Grant No.62305184)the Major Key Project of Pengcheng Laboratory(Grant No.PCL2024A1)+1 种基金the Basic and Applied Basic Research Foundation of Guangdong Province(Grant No.2023A1515012932)the Science,Technology and Innovation Commission of Shenzhen Municipality(Grant No.WDZC20220818100259004).
文摘Single-pixel imaging(SPI)enables efficient sensing in challenging conditions.However,the requirement for numerous samplings constrains its practicality.We address the challenge of high-quality SPI reconstruction at ultra-low sampling rates.We develop an alternative optimization with physics and a data-driven diffusion network(APD-Net).It features alternative optimization driven by the learned task-agnostic natural image prior and the task-specific physics prior.During the training stage,APD-Net harnesses the power of diffusion models to capture data-driven statistics of natural signals.In the inference stage,the physics prior is introduced as corrective guidance to ensure consistency between the physics imaging model and the natural image probability distribution.Through alternative optimization,APD-Net reconstructs data-efficient,high-fidelity images that are statistically and physically compliant.To accelerate reconstruction,initializing images with the inverse SPI physical model reduces the need for reconstruction inference from 100 to 30 steps.Through both numerical simulations and real prototype experiments,APD-Net achieves high-quality,full-color reconstructions of complex natural images at a low sampling rate of 1%.In addition,APD-Net’s tuning-free nature ensures robustness across various imaging setups and sampling rates.Our research offers a broadly applicable approach for various applications,including but not limited to medical imaging and industrial inspection.
基金supported by the National Natural Science Foundation of China(Grant Nos.62322502,62131003,and 62088101)the Guangdong Province Key Laboratory of Intelligent Detection in Complex Environment of Aerospace,Land and Sea(Grant No.2022KSYS016).
文摘Existing single-pixel imaging(SPI)and sensing techniques suffer from poor reconstruction quality and heavy computation cost,limiting their widespread application.To tackle these challenges,we propose a large-scale single-pixel imaging and sensing(SPIS)technique that enables high-quality megapixel SPI and highly efficient image-free sensing with a low sampling rate.Specifically,we first scan and sample the entire scene using small-size optimized patterns to obtain information-coupled measurements.Compared with the conventional full-sized patterns,small-sized optimized patterns achieve higher imaging fidelity and sensing accuracy with 1 order of magnitude fewer pattern parameters.Next,the coupled measurements are processed through a transformer-based encoder to extract high-dimensional features,followed by a task-specific plugand-play decoder for imaging or image-free sensing.Considering that the regions with rich textures and edges are more difficult to reconstruct,we use an uncertainty-driven self-adaptive loss function to reinforce the network’s attention to these regions,thereby improving the imaging and sensing performance.Extensive experiments demonstrate that the reported technique achieves 24.13 dB megapixel SPI at a sampling rate of 3%within 1 s.In terms of sensing,it outperforms existing methods by 12%on image-free segmentation accuracy and achieves state-of-the-art image-free object detection accuracy with an order of magnitude less data bandwidth.
基金supported by the National Natural Science Foundation of China(Nos.12105143 and 11975121)the China Postdoctoral Science Foundation(No.2023M741453)+1 种基金the Engineering Research Center of Nuclear Technology Application(No.HJSJYB2020-1)the Key Laboratory of Ionizing Radiation Metering and Safety Evaluation for Jiangsu Province Market Regulation,and the Jiangsu Province Excellent Postdoctoral Program(No.JB23057).
文摘Neutron-induced gamma-ray imaging is a spectroscopic technique that uses characteristic gamma rays to infer the elemental distribution of an object.Currently,this technique requires the use of large facilities to supply a high neutron flux and a time-consuming detection procedure involving direct collimating measurements.In this study,a new method based on low neutron flux was proposed.A single-pixel gamma-ray detector combined with random pattern gamma-ray masks was used to measure the characteristic gamma rays emitted from the sample.Images of the elemental distribution in the sample,comprising 30×30 pixels,were reconstructed using the maximum-likelihood expectation-maximization algorithm.The results demonstrate that the elemental imaging of the sample can be accurately determined using this method.The proposed approach,which eliminates the need for high neutron flux and scanning measurements,can be used for in-field imaging applications.
基金supported by the National Natural Science Foundation of China(Grant No.62275188)the Central Guidance on Local Science and Technology Development Fund(Grant No.YDZJSX2024D019)+1 种基金the International Scientific and Technological Cooperative Project in Shanxi Province(Grant No.202104041101009)the Natural Science Foundation of Shanxi Province of China through Research Project(Grant No.20210302123195).
文摘We propose pattern self-referenced single-pixel common-path holography(PSSCH),which can be realized using either the digital-micromirror-device(DMD)based off-axis scheme or the DMD-based phaseshifting approach,sharing the same experimental setup,to do wavefront reconstructions.In this method,each modulation pattern is elaborately encoded to be utilized to not only sample the target wavefront but also to dynamically introduce the reference light for single-pixel common-path holographic detection.As such,it does not need to intentionally introduce a static reference light,resulting in it making full use of the pixel resolution of the modulation patterns and suppressing dynamically varying noises.Experimental demonstrations show that the proposed method can not only obtain a larger field of view than the peripheral-referenced approach but also achieve a higher imaging resolution than the checkerboardreferenced approach.The phase-shifting-based PSSCH performs better than the off-axis-based PSSCH on imaging fidelity,while the imaging speed of the latter is several times faster.Further,we demonstrate our method to do wavefront imaging of a biological sample as well as to do phase detection of a physical lens.The experimental results suggest its effectiveness in applications.
基金Project supported by the National Natural Science Foundation of China(Grant No.62075241).
文摘Single-pixel imaging(SPI)can transform 2D or 3D image data into 1D light signals,which offers promising prospects for image compression and transmission.However,during data communication these light signals in public channels will easily draw the attention of eavesdroppers.Here,we introduce an efficient encryption method for SPI data transmission that uses the 3D Arnold transformation to directly disrupt 1D single-pixel light signals and utilizes the elliptic curve encryption algorithm for key transmission.This encryption scheme immediately employs Hadamard patterns to illuminate the scene and then utilizes the 3D Arnold transformation to permutate the 1D light signal of single-pixel detection.Then the transformation parameters serve as the secret key,while the security of key exchange is guaranteed by an elliptic curve-based key exchange mechanism.Compared with existing encryption schemes,both computer simulations and optical experiments have been conducted to demonstrate that the proposed technique not only enhances the security of encryption but also eliminates the need for complicated pattern scrambling rules.Additionally,this approach solves the problem of secure key transmission,thus ensuring the security of information and the quality of the decrypted images.
基金supported by the National Natural Science Foundation of China(Grant No.61271376)the Anhui Provincial Natural Science Foundation,China(Grant No.1208085MF114)
文摘The single-pixel imaging(SPI) technique is able to capture two-dimensional(2 D) images without conventional array sensors by using a photodiode. As a novel scheme, Fourier single-pixel imaging(FSI) has been proven capable of reconstructing high-quality images. Due to the fact that the Fourier basis patterns(also known as grayscale sinusoidal patterns)cannot be well displayed on the digital micromirror device(DMD), a fast FSI system is proposed to solve this problem by binarizing Fourier pattern through a dithering algorithm. However, the traditional dithering algorithm leads to low quality as the extra noise is inevitably induced in the reconstructed images. In this paper, we report a better dithering algorithm to binarize Fourier pattern, which utilizes the Sierra–Lite kernel function by a serpentine scanning method. Numerical simulation and experiment demonstrate that the proposed algorithm is able to achieve higher quality under different sampling ratios.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61405130 and 61320106015)
文摘We present an optical encryption method of multiple three-dimensional objects based on multiple interferences and single-pixel digital holography. By modifying the Mach-Zehnder interferometer, the interference of the multiple objects beams and the one reference beam is used to simultaneously encrypt multiple objects into a ciphertext. During decryption, each three-dimensional object can be decrypted independently without having to decrypt other objects. Since the single- pixel digital holography based on compressive sensing theory is introduced, the encrypted data of this method is effectively reduced. In addition, recording fewer encrypted data can greatly reduce the bandwidth of network transmission. Moreover, the compressive sensing essentially serves as a secret key that makes an intruder attack invalid, which means that the system is more secure than the conventional encryption method. Simulation results demonstrate the feasibility of the proposed method and show that the system has good security performance.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11774095,11722431 and 11621404the Shanghai Basic Research Project under Grant No 18JC1412200+2 种基金the National Key R&D Program of China under Grant No2016YFB0400904the Program of Introducing Talents of Discipline to Universities under Grant No B12024the Shanghai International Cooperation Project under Grant No 16520710600
文摘Large field-of-view（FoV） three-dimensional（3 D） photon-counting imaging is demonstrated with a single-pixel single-photon detector based on a Geiger-mode Si-avalanche photodiode. By removing the collecting lens（CL）before the detector, the FoV is expanded to ±10°. Thanks to the high detection efficiency, the signal-to-noise ratio of the imaging system is as high as 7.8 dB even without the CL when the average output laser pulse energy is about 0.45 pJ/pulse for imaging the targets at a distance of 5 m. A 3 D image overlaid with the reflectivity data is obtained according to the photon-counting time-of-flight measurement and the return photon intensity.
基金Project supported by the Natural Science Foundation of Hebei Province,China(Grant Nos.A2022201039 and F2019201446)the MultiYear Research Grant of University of Macao,China(Grant No.MYRG2020-00082-IAPME)+2 种基金the Science and Technology Development Fund from Macao SAR(FDCT),China(Grant No.0062/2020/AMJ)the Advanced Talents Incubation Program of the Hebei University(Grant No.8012605)the National Natural Science Foundation of China(Grant Nos.11204062,61774053,and 11674273)。
文摘We propose a method of complex-amplitude Fourier single-pixel imaging(CFSI)with coherent structured illumination to acquire both the amplitude and phase of an object.In the proposed method,an object is illustrated by a series of coherent structured light fields,which are generated by a phase-only spatial light modulator,the complex Fourier spectrum of the object can be acquired sequentially by a single-pixel photodetector.Then the desired complex-amplitude image can be retrieved directly by applying an inverse Fourier transform.We experimentally implemented this CFSI with several different types of objects.The experimental results show that the proposed method provides a promising complex-amplitude imaging approach with high quality and a stable configuration.Thus,it might find broad applications in optical metrology and biomedical science.
基金Project supported by the National Key Research and Development Program of China (Grant No.2018YFB0504302)。
文摘We propose a single-pixel imaging(SPI)method to achieve a higher-resolution image via the Hadamard transform matrix.Unlike traditional SPI schemes,this new method recovers images by correlating single-pixel signals with synchronized transformed patterns of Hadamard bases that are actually projected onto the digital micromirror device.Each transform pattern is obtained through the inverse Fourier transform of the pattern acquired by Gaussian filtering of each Hadamard basis in the frequency domain.The proposed scheme is based on a typical SPI experimental setup and does not add any hardware complexity,enabling the transformation of Hadamard matrices and image reconstruction through data processing alone.Therefore,this approach could be considered as an alternative option for achieving fast SPI in a diffraction-limited imaging system,without the need for additional hardware.
基金Project supported by the National Key Research and Development Program of China(Grant No.2018YFB0504302)the Youth Innovation Promotion Association of Chinese Academy of Sciencesthe National Natural Science Foundation of China(Grant Nos.11701545,11971466,and 11991021).
文摘A traditional single-pixel camera needs a large number of measurements to reconstruct the object with compressive sensing computation.Compared with the 1/0 matrices in classical measurement,the 1/-1 matrices in the complementary measurement has better property for reconstruction computation and returns better reconstruction results.However,each row of the 1/-1 matrices needs two measurements with the traditional single-pixel camera which results into double measurements compared with the 1/0 matrices.In this paper,we consider the pseudo complementary measurement which only takes the same amount of measurements with the row number of some properly designed 1/0 matrix to compute the total luminous flux of the objective and derives the measurement data of the corresponding 1/-1 matrix in a mathematical way.The numerical simulation and experimental result show that the pseudo complementary measurement is an efficient tool for the traditional single-pixel camera imaging under low measurement rate,which can combine the advantages of the classical and complementary measurements and significantly improve the peak signal-to-noise ratio.
基金supported by the Shanxi Province Science and Technology Major Special Project(No.202201010101005)the Innovation Program for Quantum Science and Technology(No.2021ZD0300705)+6 种基金the National Natural Science Foundation of China(Nos.U23A20380,62105193,62127817,62075120,62075122,U22A2091,62222509,62205187,and62305200)the China Postdoctoral Science Foundation(No.2022M722006)the National Key Research and Development Program of China(No.2022YFA1404201)the Shanxi Province Science and Technology Innovation Talent Team(No.202204051001014)the Science and Technology Cooperation Project of Shanxi Province(No.202104041101021)the Shanxi“1331 Project”111 Projects(No.D18001)。
文摘Photon-level single-pixel imaging overcomes the reliance of traditional imaging techniques on large-scale array detectors,offering the advantages such as high sensitivity,high resolution,and efficient photon utilization.In this paper,we propose a photon-level dynamic feature single-pixel imaging method,leveraging the frequency domain sparsity of the object's dynamic features to construct a compressed measurement system through discrete random photon detection.In the experiments,we successfully captured 167 and 200 Hz featured frequencies and achieved high-quality image reconstruction with a data compression ratio of 20%.Our approach introduces a new detection dimension,significantly expanding the applications of photon-level single-pixel imaging in practical scenarios.
基金sponsored by the National Natural Science Foundation of China(No.62301140)the Science and Technology Development Plan Project of Jilin Province of China(No.20220204134YY)+2 种基金the Program for Science and Technology Development of Changchun City(No.23YQ01)the Project of the Education Department of Jilin Province(Nos.JJKH20250305BS and JJKH20250302KJ)the Fundamental Research Funds for the Central Universities(No.2412024QD005)。
文摘Cross-species pose estimation plays a vital role in studying neural mechanisms and behavioral patterns while serving as a fundamental tool for behavior monitoring and prediction.However,conventional image-based approaches face substantial limitations,including excessive storage requirements,high transmission bandwidth demands,and massive computational costs.To address these challenges,we introduce an image-free pose estimation framework based on single-pixel cameras operating at ultra-low sampling rates(6.260×10^(-4)).Our method eliminates the need for explicit or implicit image reconstruction,instead directly extracting pose information from highly compressed single-pixel measurements.It dramatically reduces data storage and transmission requirements while maintaining accuracy comparable to traditional image-based methods.Our solution provides a practical approach for real-world applications where bandwidths and computational resources are constrained.
基金supported by the Innovation Project of Optics Valley Laboratory(No.OVL2023ZD005).
文摘Existing two-step Fourier single-pixel imaging (FSPI) suffers from low noise-robustness, and three-step FSPI and four-step FSPI improve the noise-robustness but at the cost of more measurements. In this Letter, we propose a method to improve the noise-robustness of two-step FSPI without additional illumination patterns or measurements. In the proposed method, the measurements from base patterns are replaced by the average values of the measurement from two sets of phase-shift patterns. Thus, the imaging degradation caused by the noise in the measurements from base patterns can be avoided, and more reliable Fourier spectral coefficients are obtained. The imaging quality of the proposed robust two-step FSPI is similar to those of three-step FSPI and four-step FSPI. Simulations and experimental results validate the effectiveness of the proposed method.
文摘Hyperspectral-depth imaging is of great importance in many fields.However,it is difficult for most systems to achieve good spectral resolution and accurate location at the same time.Here,we present a hyperspectral-depth single-pixel imaging system that exploits the two reflection beam paths of a spatial light modulator to provide one-dimensional depth and spectral information of the object;then,they are combined with the modulation patterns and compressed-sensing algorithm to construct the hyperspectral-depth image,even at a sampling ratio of 25%.In our experiments,a spectral resolution of 1.2 nm in the range of 420 to 780 nm is achieved,with a depth measurement error of less than 1 cm.Our work thus provides a new way for hyperspectral-depth imaging.
基金supported by the National Natural Science Foundation of China(Nos.12471368,12325408,12274129,12274139,and 62475070)the Fundamental and Applied Basic Research Project of Guangzhou(No.2024A04J2001)the Guangdong Basic and Applied Basic Research Foundation(No.2024B1515020051)。
文摘Single-pixel imaging(SPI)is a computational imaging technique that is able to reconstruct high-resolution images using a single-pixel detector.However,most SPI demonstrations have been mainly focused on macroscopic scenes,so their applications to biological specimens are generally limited by constraints in space-bandwidth-time product and spatial resolution.In this work,we further enhance SPI's imaging capabilities for biological specimens by developing a high-resolution holographic system based on heterodyne holography.Our SPI system achieves a space-bandwidth-time product of 41,667 pixel/s and a lateral resolution of 4±5μm,which represent state-of-the-art technical indices among reported SPI systems.Importantly,our SPI system enables detailed amplitude imaging with high contrast for stained specimens such as epithelial and esophageal cancer samples,while providing complementary phase imaging for unstained specimens including molecular diagnostic samples and mouse brain tissue slices,revealing subtle refractive index variations.These results highlight SPI's versatility and establish its potential as a powerful tool for advanced biomedical imaging applications.
基金supported by the Natural Science Foundation of China Project(No.62031011).
文摘Single-pixel imaging(SPI)is a prominent scattering media imaging technique that allows image transmission via one-dimensional detection under structured illumination,with applications spanning from long-range imaging to microscopy.Recent advancements leveraging deep learning(DL)have significantly improved SPI performance,especially at low compression ratios.However,most DL-based SPI methods proposed so far rely heavily on extensive labeled datasets for supervised training,which are often impractical in real-world scenarios.Here,we propose an unsupervised learningenabled label-free SPI method for resilient information transmission through unknown dynamic scattering media.Additionally,we introduce a physics-informed autoencoder framework to optimize encoding schemes,further enhancing image quality at low compression ratios.Simulation and experimental results demonstrate that high-efficiency data transmission with structural similarity exceeding 0.9 is achieved through challenging turbulent channels.Moreover,experiments demonstrate that in a 5 m underwater dynamic turbulent channel,USAF target imaging quality surpasses traditional methods by over 13 dB.The compressive encoded transmission of 720×720 resolution video exceeding 30 seconds with great fidelity is also successfully demonstrated.These preliminary results suggest that our proposed method opens up a new paradigm for resilient information transmission through unknown dynamic scattering media and holds potential for broader applications within many other scattering media imaging technologies.
基金National Natural Science Foundation of China,Grant/Award Numbers:52090030,52090031,92164106,U22A2076Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering,Grant/Award Number: 2022SZ-TD011+1 种基金National KeyResearch and Development Program ofChina, Grant/Award Numbers:2022YFA1204300, 2022YFA1204304,2022YFA1204900Fundamental ResearchFunds for the Central Universities,Grant/Award Number: 2021FZZX001-17。
文摘The demand for high-performance X-ray detectors leads to material innovationfor efficient photoelectric conversion and carrier transfer. However, currentX-ray detectors are often susceptible to chemical and irradiation instability,complex fabrication processes, hazardous components, and difficult compatibility.Here, we investigate a two-dimensional (2D) material with a relativelylow atomic number, Ti_(3)C_(2)T_(x) MXenes, and single crystal silicon for X-ray detectionand single-pixel imaging (SPI). We fabricate a Ti_(3)C_(2)T_(x) MXene/Si X-raydetector demonstrating remarkable optoelectronic performance. This detectorexhibits a sensitivity of 1.2 × 10^(7) μC Gyair^(-1) cm^(-2), a fast response speed with arise time of 31 μs, and an incredibly low detection limit of 2.85 nGyair s^(-1).These superior performances are attributed to the unique charge couplingbehavior under X-ray irradiation via intrinsic polaron formation. The deviceremains stable even after 50 continuous hours of high-dose X-ray irradiation.Our device fabrication process is compatible with silicon-based semiconductortechnology. Our work suggests new directions for eco-friendly X-ray detectorsand low-radiation imaging system.
文摘Single-pixel imaging (SPI) captures two-dimensional images utilizing a sequence of modulation patterns and measurements recorded by a single-pixel detector. However, the sequential measurement of a scene is time-consuming, especially for high-spatial-resolution imaging. Furthermore, for spectral SPI, the enormous data storage and processing time requirements substantially diminish imaging efficiency. To reduce the required number of patterns, we propose a strategy by optimizing a Hadamard pattern sequence via Morton frequency domain scanning to enhance the quality of a reconstructed spectral cube at low sampling rates. Additionally, we expedite spectral cube reconstruction, eliminating the necessity for a large Hadamard matrix. We demonstrate the effectiveness of our approach through both simulation and experiment,achieving sub-Nyquist sampling of a three-dimensional spectral cube with a spatial resolution of 256×256 pixels and181 spectral bands and a reduction in reconstruction time by four orders of magnitude. Consequently, our method offers an efficient solution for compressed spectral imaging.
