49 results about "Phase retrieval" patented technology

The invention discloses a depth physical parameter integrated network and method for lensless microscopic imaging, and the method comprises the steps: firstly building a physical forward model based on fractional Fourier transform, and quantizing a propagation distance into an adjustable fractional order parameter; secondly, constructing a multi-stage progressive network framework, wherein each stage comprises a physical model fidelity module and an image regularization updating module; a self-adaptive near-end network and a self-adaptive compression-excitation network are innovatively embedded in a regularization module, and real-time self-adaption of network parameters to imaging conditions is achieved; finally, end-to-end single-frame reconstruction is realized, complex amplitude information is directly recovered from a single intensity observation image, and retraining for different imaging parameters is not needed. According to the method, the reconstruction physical reliability, the noise robustness and the cross-scene generalization ability are remarkably improved, meanwhile, the lightweight real-time deployment requirement is met, and the method is suitable for lens-free microscopic imaging scenes such as biological living body observation and portable pathological diagnosis.

The invention discloses a multi-particle three-dimensional shape reconstruction method based on projection consistency. According to the method, a three-angle laser interference particle imaging system is used for collecting out-of-focus images of three visual angles, a center M * N pixel range is cut to obtain an out-of-focus speckle image, phase recovery algorithm reconstruction is carried out, a two-dimensional particle shape is obtained, a gray threshold value above 70 is set to be a target contour area, binarization segmentation is carried out, and a target contour image is obtained. And smoothing the target contour area. And carrying out three-dimensional space projection on contours of the four candidate results in Matlab, generating a three-dimensional structure in an intersection region, re-projecting the three-dimensional structure to each view angle, calculating an error S between a re-projected image and an original input projection, and selecting a final reconstruction result with the minimum S. According to the method, through systematic iterative optimization and an error evaluation mechanism, trivial fuzzy interference in a phase recovery process is effectively eliminated, and high-precision reconstruction of a multi-particle three-dimensional shape is realized.

The invention belongs to the technical field of metasurface electromagnetic regulation and control, and particularly relates to a computer-aided design broadband stealth phase recovery method and a broadband carpet stealth device. The broadband carpet stealth device is specifically represented as a triangular split platform with the inclination angle phi, and the surface of the broadband carpet stealth device is formed by periodically arranging M * N metasurface units. The broadband stealth phase recovery method is based on a gradient descent method and a root search algorithm, and relates to two phase regulation and control modes. Firstly, M / 2 unit structure parameters are determined based on a gradient descent method, and each unit is composed of an upper-layer multi-mode metal resonator loaded with a variable capacitance diode, a middle-layer F4B dielectric plate and a lower-layer metal floor; and secondly, searching voltages required in three application scenes point by point in a broadband range through a root seeking algorithm, and outputting the voltages in real time by adopting a field programmable gate array so as to accurately recover a scattering electromagnetic wave phase, so that a broadband electromagnetic illusion function is realized. The carpet hiding device works under linear polarized waves, and has the advantages of being high in efficiency, easy to process, programmable and the like.

The invention relates to methods and apparatuses for reconstructing phase information in a time series, the time series being derived from a time evolution of an input state acted on by a Hamiltonian, H. First, an input state, |ψ, a total time evolution time, T, and the Hamiltonian, H are received. Next a time evolution of the input state is enacted, using H to generate an absolute value of a first time series, |f1|. In addition at least one additional family of absolute values of time series is generated, each time series being a discrete or continuous function of time t, for t∈[0,T]. Finally, phase information is extracted for the time series of the input state from the absolute values of the first time series and the at least one additional family of absolute values of time series.

The invention discloses an ultrafast coherent modulation imaging device based on chirped pulse illumination, which can collect evolution information of intensity and phase along with time change in an ultrafast dynamic scene under the condition of single exposure. The device encodes an ultrafast scene by using the spectrum-time mapping characteristic of chirped pulses, realizes phase encoding through random phase modulation, then acquires an encoded diffraction pattern through a snapshot hyperspectral camera, and finally recovers space-time complex amplitude information of the ultrafast dynamic scene through a phase retrieval algorithm. The invention provides an imaging device capable of obtaining dozens of ultrafast time resolution complex amplitude images in single exposure, and the imaging dimension and the time resolution capability are remarkably improved. The device and method provided by the invention provide a new technical path for researching the ultrafast dynamic process, and have certain scientific research application potential and engineering popularization value.

The invention relates to the technical field of optics, in particular to a multi-channel CPO optical engine automatic calibration method and system for machine vision, and the method comprises the steps: building an optical-mechanical-electrical coupling state space model based on a vector diffraction theory and a four-order ABCD optical path transfer matrix; performing multi-scale grating dot matrix pattern projection through a tunable structure grating and a sequential control light source, and synchronously acquiring temperature and attitude data to obtain an observation frame; local complex amplitude reconstruction and splicing are realized by adopting sparse phase retrieval and a block Fourier frequency domain splicing method, and a space-wavelength-temperature three-dimensional error tensor is generated; calculating an optimal compensation vector by applying a self-adaptive extended Kalman filter and a Bayesian forgetting coefficient; and dynamically rewriting a digital-to-analog conversion look-up table according to the compensation vector to realize electric, thermal and optical closed-loop adjustment. According to the method provided by the invention, stable and high-precision automatic calibration of the CPO light engine can be realized.

The invention discloses an optical element surface defect depth detection method and system based on an iterative phase retrieval algorithm, and relates to the field of optical element surface defect depth detection.The system comprises an imaging module and a control module, the imaging module is used for obtaining a focusing intensity image and a defocusing intensity image of a sample; and the control module is used for realizing defect depth detection according to the focusing intensity image and the defocusing intensity image of the sample by adopting an optical element surface defect depth detection method based on an iterative phase recovery algorithm. According to the invention, an accurate depth detection result can be rapidly obtained.

The invention relates to the technical field of underwater imaging, provides a Fourier lamination underwater imaging system and method based on adaptive phase retrieval, and effectively solves the problem of insufficient imaging resolution caused by a strong scattering effect of a water body and aperture limitation of an optical system in a traditional underwater imaging technology. According to the method, the Fourier lamination imaging technology is applied to the underwater environment for the first time, and the spatial resolution is improved by 2.24 times compared with that of a traditional method in combination with the self-adaptive phase retrieval algorithm. Further experiments show that even under the strong scattering condition, the scheme can still keep the resolution performance obviously superior to that of a traditional method. The invention provides a novel underwater high-resolution imaging technical scheme, the imaging performance of marine resource exploration and underwater engineering facility detection can be remarkably improved, and the method has important application value.

The application discloses a digital phase-shifting phase recovery method of ESPI fringe pattern based on distance mapping, which comprises the following steps: 1) extracting the direction of each pixel point of the fringe pattern, and then calculating the normal curve of the fringe according to the fringe direction to obtain the moving direction of the fringe; 2) extracting the center line of the dark fringe, calculating the width of the fringe according to the center line of the fringe, and obtaining the moving distance of the fringe through distance mapping; 3) comprehensively moving the direction and the distance, and performing digital phase-shifting on the initial fringe pattern point by point, and adopting the bilinear gray interpolation to obtain the fringe pattern after digital phase-shifting; 4) calculating the wrapped phase corresponding to the fringe pattern; and 5) performing unwrapping processing on the wrapped phase to recover the full-field phase of the fringe pattern. The application extracts the phase through the digital image processing technology on the single fringe pattern, avoids the problem of inaccurate phase-shifting existing in the traditional physical phase-shifting technology in dynamic measurement, and can effectively improve the accuracy of the phase recovery of the single fringe pattern.

The application discloses a kind of irregular particle shape reconstruction methods based on phase recovery, builds interference particle imaging system;In defocus image plane obtains the defocus speckle image I of irregular particle to be measured M ; The defocus speckle image I M It is sheared, and the speckle region image I located in the center position and the size of N×N after shearing is retained;Speckle region image I is input into phase recovery algorithm model and iterative calculation is carried out, and preliminary reconstruction result is obtained;Proportion factor factor SF is set, and the preliminary reconstruction result of the above iteration, i.e. new particle estimate p k+1 (x0,y0) is scaled with proportion factor SF, and final reconstruction particle shape is obtained.Compared with prior art, the application can directly obtain accurate shape information of irregular particle through particle interference defocus image, without additional optical path setting, and the device is simple, which provides basis for the measurement of complex particle field.

The present invention discloses a computational imaging method for non-phase frequency diversity based on VAE-GAN, comprising the following steps: S1, constructing a mathematical model for near-field imaging of a metasurface antenna; S2, based on the mathematical model for near-field imaging of a metasurface antenna, and by combining deep neural network and compressive sensing technology, constructing a PFDCI-Net imaging network; S3, designing a network training algorithm for the PFDCI-Net imaging network, and optimizing the PFDCI-Net imaging network to minimize the loss of the PFDCI-Net imaging network; S4, using the target FMNIST data and the target MNIST dataset to train the PFDCI-Net imaging network to obtain the scattering coefficients for reconstructing the target scene. The computational imaging method proposed by the present invention completely avoids the errors caused by phase retrieval, reduces the computational complexity of the frequency diversity CI reconstruction problem, and improves the imaging accuracy and efficiency.

A method for phase retrieval, the method may include (a) obtaining multiple out-of-focus intensity images of one or more point spread function targets; wherein the out-of-focus intensity images are generated by based on residual collected light signals obtained by a residual collection channel of an optical unit having a numerical aperture that exceeds 0.8; and (b) calculating phase information, based on the multiple out-of-focus intensity images and on a vectorial model of the point spread function.

The invention belongs to the technical field of optical detection, and particularly relates to the field of optical wavefront detection, in particular to a lateral shear interference wavefront detection system and method based on an orthogonal polarization birefringent crystal. The system comprises a laser light source, wherein a polarizer and a beam splitter prism are sequentially arranged on an emergent light path of the laser light source; the invention discloses a polarization birefringent crystal, a reflector and a polarization camera. The method comprises the following steps: processing four phase shift interferograms, and extracting a wavefront gradient by using an arc tangent function; solving the system of linear equations to determine wavefront phase distribution by adopting an integral algorithm based on a least square method; and based on the extracted wavefront gradient, performing quantitative phase imaging by using a phase recovery algorithm. The device is simple in structure, high in stability and high in light energy utilization rate; the method is good in real-time performance, high in precision, capable of effectively restraining noise influences, capable of improving the precision of wavefront measurement, capable of meeting the requirement for high-precision optical system detection and wide in application range.

This invention discloses a phase retrieval method for bright-field microscopy based on uniform light intensity, belonging to the technical field of phase retrieval in optical measurement. The method includes: acquiring focused light intensity images, positive defocus images, and negative defocus images along the optical axis; calculating the axial differential of light intensity using the finite difference method; simplifying the light intensity transmission equation to a Poisson equation and solving the Poisson equation to obtain the initial phase; constructing a positive higher-order error compensation model for the axial differential of light intensity and solving for the phase; and using a gradient acceleration strategy to iteratively calculate the phase to obtain the final phase result. This invention significantly improves the stability and accuracy of phase retrieval. Simultaneously, by combining angular spectrum theory to construct an axial differential higher-order error compensation model and introducing a gradient acceleration strategy, it effectively corrects defocus errors, greatly improves iterative convergence efficiency, and enhances the applicability of the method in practical microscopic imaging scenarios.

This invention discloses a single-frame coded phase retrieval system and parameter calibration method based on iterative filtering inversion, belonging to the field of lensless computational microscopy imaging technology. It solves the problems of mismatch between single-frame coded phase retrieval algorithms and complex coding scenarios, difficulty in balancing noise suppression and resolution, large system diffraction distance estimation errors, and inaccurate wavefront lateral offset calibration, leading to low imaging accuracy and poor stability. This invention constructs a system including a light source, replaceable amplitude / phase coding, CMOS imaging, one-dimensional electric displacement drive, and a built-in IrCPR algorithm control module, along with a process of "multi-distance calibration of coding functions → Z1 / Z2 calibration using ToG / SG according to coding board type → cross-correlation spectrum registration." This invention improves the accuracy of coding function calibration and diffraction distance estimation, achieves pixel-level alignment of the coded wavefront, and completes complex amplitude reconstruction with a single frame acquisition. The system has strong adaptability and stability, making it suitable for high-precision microscopy imaging scenarios.

A synthetic aperture quantitative phase imaging method based on a hybrid of digital holography and Fourier ptychography. A programmable LED array which is annularly arranged is mounted on an off-axis digital holographic system for providing oblique illumination at varying angles; accurate noise-containing low-frequency information of an object is obtained by means of digital holography and is used as initial estimation; and then, high-frequency information of the object is reconstructed by means of a Fourier ptychographic algorithm based on intensity measurement, so as to realize synthetic aperture quantitative phase imaging. Using the accurate low frequency provided by holography as initial estimation ensures the accuracy of phase retrieval and wavefront aberration reconstruction, without strictly meeting matching illumination conditions, and reduces the number of intensity graphs required by Fourier ptychography; and a non-interferometric phase retrieval method based on Fourier ptychography improves the imaging resolution to an incoherent diffraction limit, and also effectively solves the problem of inherent speckle noise in digital holography.

This invention discloses a method and system for integrated communication and sensing based on a large-scale intelligent reflector-assisted system. First, the invention characterizes the problems of channel estimation, beamforming design, and user location estimation during large-scale model training. Then, it designs a multi-task context learning mechanism, heterogeneous data reconstruction, and three network modules to organically incorporate three physically semantically distinct integrated communication and sensing tasks—channel estimation, beamforming design, and user location—into a unified model. Based on the uplink pilot signal sent by the user, the invention achieves the aforementioned three typical integrated communication and sensing tasks. Furthermore, this invention provides a differentiable reparameterized phase retrieval strategy for intelligent reflector phase shift, ensuring that the model output strictly meets hardware physical constraints. This overcomes the limitation of existing networks that can only handle single tasks, providing an efficient solution for large-scale intelligent reflector-assisted integrated communication and sensing.

The phase recovery and conjugate image suppression method for multi-wavelength lensless microscopic cell imaging belongs to the field of cell lensless microscopic imaging technology in the biological and pharmaceutical industries. It solves the problem that the existing technology does not consider the sub-pixel displacement between different holograms, which is not only cumbersome but also affects the effect and accuracy of image processing. The light intensity information under red light irradiation, the light intensity information under green light irradiation, and the light intensity information under blue light irradiation are obtained respectively; the optimal reproduction distance of the holographic microscopic image under the red light wavelength, the optimal reproduction distance of the holographic microscopic image under the green light wavelength, and the optimal reproduction distance of the holographic microscopic image under the blue light wavelength are respectively found; based on the light wave complex amplitude distribution of the reconstructed image plane under red light irradiation, the light wave complex amplitude distribution of the reconstructed image plane under green light irradiation, and the light wave complex amplitude distribution of the reconstructed image plane under blue light irradiation, the phase distribution for suppressing the conjugate image is obtained.

This application belongs to the field of light field display technology, specifically disclosing a rigorous scalar light field calculation and solution method and system. It includes: obtaining the complex amplitude distribution on the source plane; and calculating the rigorous scalar light field distribution on the observation plane based on rigorous scalar diffraction theory and the complex amplitude distribution on the source plane. Based on scalar diffraction theory, this application constructs a light field propagation model for arbitrary propagation distances, avoids approximation errors in geometric correction methods through a rigorous scalar light field propagation method, overcomes the propagation distance constraints of the scalable angular spectrum propagation model, and achieves Abbe diffraction-limited resolution through a phase retrieval algorithm.

Concepts for multi-energy dark-field (DAX) and phase-contrast (PC) X-ray imaging are proposed. One such concept comprise acquiring a set of low energy images with phase stepping and a set of high energy images (with or without phase stepping). Transmission, DAX, and PC images are obtained from the phase-stepped low energy images using phase retrieval. Also, a high energy transmission image is obtained from the high energy image(s). Based on the transmission image from the low energy images and the transmission image from the high energy image(s), a modified transmission image is generated.

Herein is presented a method for the adaptive correction of images comprises the steps: (a) capturing a first image with an image capture device; (b) selecting within the first image at least one candidate point and at least two test points; (c) using an iterative phase retrieval algorithm to calculate for each of the at least one candidate points an initial aberration correction for the entire image as if each of said at least one candidate points were guiding stars; (d) comparing the aberrations of each of the at least two test points in each of the initial aberrations corrections; (e) selecting the one candidate point whose initial aberration correction yields suitably similar aberrations for each of the at least two test points and designating said candidate point as a virtual guiding star; and (f) calculating phase corrections for the initial aberrations according to said virtual guiding star.

The disclosure herein provides a device, a method and a computer-readable storage medium for quantitative phase imaging, and relates to the field of quantitative phase imaging. The specific implementation scheme is: Obtain a multiplexed interferogram of the sample, where the multiplexed interferogram is a sample beam composed of at least two beams with different wavelengths to illuminate the sample and penetrate into the cube beam splitter Combine at least two beams with different wavelengths as the reference beam, and the combined beam is the imaging image sampled by the camera; and perform phase retrieval on the multiplexed interference image to obtain each beam of the sample in the composite sample beam The phase map at the wavelength of. Using the embodiments of the disclosure herein, one imaging acquisition and one phase retrieval are to acquire the phase maps of at least two wavelength channels.

This application provides a dynamic multifunctional optical metasurface design method and system. The method includes: acquiring functional requirements under different application scenarios and setting the target reflection spectrum accordingly; inputting the target reflection spectrum into a reverse retrieval network, which is then compressed by an encoder and predicted by a decoder parameter to obtain the predicted design parameters of the meta-unit structure; inputting the predicted design parameters of the meta-unit structure into a forward prediction network, which is then calculated via forward propagation to obtain the predicted reflection spectrum; based on the degree of matching between the predicted reflection spectrum and the target reflection spectrum, a phase retrieval algorithm is used to establish a bidirectional connection between the design domain and the physical domain, and by continuously adjusting the predicted design parameters of the meta-unit structure, the predicted reflection spectrum gradually approaches the target reflection spectrum to obtain the ideal design parameters of the meta-unit structure; and arranging the meta-units in the operating space according to the ideal design parameters of the meta-unit structure to form a metasurface structure that can be dynamically and multifunctionally controlled.

The application provides a phase retrieval method, device, system and medium based on enhanced total variation regularization, and relates to the technical field of image processing. The method comprises the following steps: constructing a non-convex optimization model for phase retrieval based on an enhanced total variation regularization model and a phase retrieval problem model; converting the non-convex optimization model into a convex optimization model by using a convex function difference algorithm; obtaining an image to be recovered, inputting the image to be recovered into the convex optimization model, iteratively solving the convex optimization model by using an alternating direction multiplier method, and obtaining a recovered image. The application can improve the definition of the recovered image.

The application discloses an EUV-OCT phase recovery method based on deep learning U-Net, and comprises the following steps: acquiring reflectivity spectrum data of a multi-layer sample and preprocessing; constructing and training a physical driving phase recovery network based on U-Net, wherein a double-branch feature embedding module is used for simultaneously extracting local interference fringes and depth envelope features; a physical driving state space module regards one-dimensional spectrum features as continuous dynamics, and realizes feature transmission of a global receptive field through a discrete state space equation; gradient phase perception attention guided skip connection enhances phase mutation point features; a complex domain output module predicts phase sine / cosine components and restores continuous phase by using an inverse tangent operator; and the measured reflectivity spectrum is input into the trained network, and a phase spectrum with physical continuity is output. The application can adapt to different experimental bandwidths, fundamentally eliminates phase jump artifacts, and significantly improves the accuracy and robustness of phase recovery.

This invention belongs to the field of optical communication and relates to a signal phase recovery method, apparatus, device, and medium based on maximum a posteriori probability symbol decision error. The method includes the following steps: performing symbol decision on the received signal based on maximum a posteriori probability and calculating the symbol decision error; constructing an error function based on the symbol decision error and calculating the gradient of the error function with respect to the phase noise value; updating the phase estimate along the gradient descent direction; and performing phase noise recovery of the symbol based on the phase estimate to obtain the phase-recovered output signal. Compared with existing technologies, this invention combines the error gradient descent algorithm with high-performance phase recovery to meet the compensation requirements for severe linear random phase noise generated by laser linewidth in coherent transmission. Simultaneously, the symbol decision error-based approach improves the accuracy of phase noise estimation while effectively avoiding the use of time windows, thus reducing computational complexity.

The invention discloses a blind single phase recovery method based on a self-supervised physical adaptive network, and relates to the technical field of optical imaging. Establishing a blind phase recovery method based on self-supervision in a coherent diffraction system of an optical propagation theory, and jointly optimizing physical parameters and a target image; according to a physical propagation model based on an angular spectrum method, the optimized target image is converted into network parameter optimization, and a corresponding single reconstruction image and a corresponding diffraction distance are obtained through simulation; establishing a physical adaptive network, taking an acquired real diffraction pattern as input, converting phase information into physical parameters, and realizing reconstruction of a blind image and accurate estimation of the physical parameters; a fine physical consistent loss function and a self-supervised training model are established, optimization of physical parameters and network parameters is jointly constrained through two parts of detail loss and structure loss, and a micro-penalty mechanism is introduced to guide training. According to the method, the problem of blind single-frame phase recovery is solved, and excellent stability and robustness are ensured.

The application provides a signal reconstruction method, system, device and storage medium, which is used for reconstructing an original signal from a measurement signal containing only amplitude information, and comprises the following steps: obtaining the measurement signal containing only amplitude information by using a measurement device, and recording a measurement matrix corresponding to the measurement device; establishing a denoiser, and taking a function feature of the denoiser as denoising prior information; under the regular constraint based on the denoiser prior information, establishing a non-convex optimization inverse problem of signal reconstruction, and iteratively solving the problem by using a projection gradient method; and introducing the denoiser in the solving step, so that the convergence speed of the algorithm is improved. The application combines a solving algorithm of a traditional non-convex optimization problem with denoising prior, improves the reconstruction performance of a signal in a complex Gaussian random measurement matrix and coded diffraction imaging, guarantees convergence, reduces the necessary number of measurement signals, and meets the current demand for signal phase retrieval and reconstruction.

The invention discloses a non-vision-field high-resolution scattering imaging method based on speckle fingerprints, and the method comprises the steps: shooting a series of speckle images based on a built non-vision-field imaging optical system; any two speckle images are selected from the speckle images for frequency domain filtering processing, an envelope is obtained from low-frequency information, and spatial normalized speckles are obtained from high-frequency information; according to the obtained envelopes, calculating the cross-correlation of the envelopes corresponding to the two speckles to obtain corresponding target displacement information, and calculating the corresponding position of the autocorrelation value on the target autocorrelation; combining the obtained autocorrelation value and the corresponding position thereof into a pixel on target autocorrelation; and through loop iteration, constructing a complete target self-correlation image containing all pixels, and reconstructing a target image O through a phase retrieval algorithm. According to the method, high-resolution imaging and tracking of the moving target in the non-vision-field mode can be realized, prior knowledge and invasive operation are not needed, the accuracy of image recovery is improved, and a new effective means is provided for solving the non-vision-field imaging problem.