116 results about "Phase map" patented technology

The invention relates to the technical field of optical precision interference measurement, in particular to a correction method for projection distortion detection of a primary mirror of a dynamic interferometer and a related product, and the method comprises the steps: obtaining a first coordinate and a second coordinate; determining a zero distortion point; obtaining an ideal imaging point set and an actual mapping point set after system projection through ray tracing; fitting to obtain a distortion function representing the distortion of the optical system; performing point-by-point correction on a phase diagram obtained by interference measurement, mapping pixel coordinates of the phase diagram into workpiece coordinates, obtaining interference measurement data corresponding to the actual surface of the primary mirror, and completing distortion correction; according to the method for correcting the surface shape projection distortion during interference measurement of the high-precision primary mirror of the large-aperture dynamic interferometer, the problem that in the process of assembling, repairing and developing the large-aperture Twyman type dynamic interferometer, the projection distortion effect of a detection system causes the loss of an accurate matching relation between a workpiece coordinate system and a detection coordinate system is solved.

The invention relates to a synthetic aperture radar interferometry phase unwrapping method based on a convolutional neural network and a visual converter, and belongs to the technical field of synthetic aperture radar interferometry. Aiming at the problem that a traditional deep learning method is insufficient in phase unwrapping precision in a complex terrain and noise environment, the method comprises the following steps of inputting a synthetic aperture radar interferogram to be unwrapped, extracting local features by using a convolutional neural network, generating a fusion feature map through a multi-scale feature capture module, and performing phase unwrapping on the fusion feature map; and after channel weights are adjusted through an extrusion-excitation network, a single-head self-attention mechanism is applied to capture a global relationship, and finally a continuous phase diagram is reconstructed through a convolutional layer. According to the method, local feature extraction and global relation modeling are effectively combined, the processing capacity for a phase jump area and noise is improved, the method is suitable for phase unwrapping of large-gradient surface deformation areas such as mining areas, continuous phase information in interference measurement can be accurately recovered, and accurate data support is provided for application such as surface deformation monitoring.

The invention discloses a light field display method and system with holography as a representation medium, and the method comprises the following steps: S1, collecting a multi-view image of a target scene, carrying out the coding of the multi-view image, and generating a light field tensor containing space and angle information; s2, mapping the light field tensor in the step S1 into a two-dimensional space phase diagram; s3, converting the two-dimensional space phase diagram in the step S2 into a modulation diagram used for driving a spatial light modulator; and S4, driving the spatial light modulator to perform light wavefront modulation according to the modulation graph in the step S3, and reproducing the image of the target scene through optical diffraction. According to the invention, integration from dynamic scene information acquisition to high-quality three-dimensional image reproduction is realized, a low-redundancy and high-fidelity processing link is realized, and the efficiency and quality of holographic display are greatly improved.

The invention discloses a field calibration method and system for SMT 3D AOI equipment, and relates to the surface mounting technology, and the method comprises the steps: feeding a calibration board into the SMT 3D AOI equipment according to the same board feeding mode as a common PCB, and carrying out the initialization; multiple groups of horizontal and vertical grating images are acquired; performing phase calculation on the grating image acquired by the camera by using a phase shift method to obtain a plurality of groups of horizontal and vertical phase diagrams; performing image processing on the calibration plate image acquired by the camera, calculating circle center coordinates of all the circular patterns, and calculating corresponding point coordinates of the circle center coordinates on the imaging plane of each projector; calculating coordinate values of all circle centers on the calibration plate in a world coordinate system according to the adopted Z-axis height and the distance between the circular patterns of the calibration plate; repeatedly calculating world coordinates; and determining optimized system parameters according to the projection process of conversion from the coordinate values of the world coordinate system to the camera pixel coordinate system. According to the invention, the internal parameters and the external parameters of the equipment can be quickly optimized, and the precision of the imaging system is recovered to the initial state.

The invention relates to a speckle interferometric phase diagram filtering method based on a conditional diffusion model, and belongs to the technical field of optical measurement. The method comprises the following steps: S1, obtaining training data: generating or collecting multiple groups of paired speckle interferometric phase diagrams including noisy speckle interferometric phase diagrams and corresponding denoising reference phase diagrams; s2, constructing a conditional diffusion model; S3, training the conditional diffusion model: training the diffusion model in a supervision mode; and S4, taking the to-be-processed phase diagram as a conditional image, and generating a denoised phase diagram through a back diffusion process. According to the invention, the noise processing accuracy of the phase diagram in laser speckle interference measurement can be improved.

The invention discloses an image-based suspension bridge surface anomaly measurement method and measurement system, and relates to the technical field of optical measurement and image processing. The method comprises the following steps: projecting a first polarization grating and a second polarization grating with mutually orthogonal polarization directions to a to-be-measured area of the suspension bridge in a time-sharing manner; polarization information of reflected light is collected by adopting a polarization state imaging unit, and corresponding first and second Moire phase diagrams are generated. The data processing unit further performs double-path parallel processing on the two Moire phase diagrams: on one hand, a two-dimensional inclined field representing the macroscopic contour of an object is solved through a joint solution algorithm; and on the other hand, through differential operation, microscopic optical anisotropy abnormal points caused by material stress, damage and the like are identified and positioned by utilizing symmetrical response of the optical isotropic surface to the orthogonal grating. The method realizes synchronous decoupling of geometric and physical characteristics from a single data source through one-time measurement, has the advantages of non-contact and high efficiency, and is suitable for precise detection of large-scale structures such as a suspension bridge and the like.

Embodiments of the present application provide a deep learning-based phase unwrapping method and apparatus, a device, and a medium. The method comprises: acquiring a wrapped phase map; and inputting the wrapped phase map into a pre-trained deep learning network model and performing phase unwrapping, such that the deep learning network model outputs, on the basis of a non-linear mapping relationship between wrapped phases and absolute phases, an absolute phase map corresponding to the wrapped phase map, wherein the deep learning network model adopts a U-Net framework and comprises an encoder, a decoder, a deep-supervision feature fusion module, and an atrous spatial pooling pyramid module, and the encoder and the decoder comprise Inception modules. On this basis, even in high-noise environments and in the presence of phase discontinuity, the embodiments of the present application enable a trained deep learning network model to predict a high-quality absolute phase map in just one step, thereby achieving accurate phase unwrapping.

This invention discloses a three-dimensional contour measurement method and apparatus based on multi-projection gratings, relating to the field of three-dimensional topography measurement technology. The method includes: obtaining intrinsic and extrinsic parameters through calibration; projecting a set of speckle patterns; preliminarily analyzing the surface topography gradient of the object to determine a non-uniform spatial frequency sequence; sequentially projecting and acquiring multiple sets of phase-shifting grating patterns, and calculating the wrapping phase map corresponding to each frequency; for the same pixel, based on its reliability assessment in wrapping phase maps at different frequencies, assigning confidence weights to the phase values ​​of each frequency, and calculating and optimizing the phase map and the corresponding fused confidence map; calculating gradient information and combining it with the fused confidence map to perform region division, and executing a region-guided path consistency verification unfolding algorithm to obtain the absolute phase; converting the absolute phase into three-dimensional point cloud coordinates of the object surface. This application aims to solve the problems of complex topography, discontinuities, and noise easily leading to unfolding path errors and order jumps during phase unfolding.

The present application relates to the field of information optics, more particularly, to a spatial structure vertical focal field generation method and system. The present application provides a spatial structure vertical focal field generation method, according to the constructed phase map of the spatial structure vertical focal field, the incident light beam is modulated into a cylindrical wave light beam at the light beam modulation, and then the cylindrical wave light beam is focused to generate a spatial structure vertical focal field. Wherein, the phase map only needs to be calculated according to the superposition of the column lens phase or the column lens phase and the flash grid phase, and the calculation amount and calculation time are obviously reduced compared with the iterative calculation of the existing method. The present application solves the problems of large calculation amount and long time consumption of the existing method for generating a spatial structure vertical focal field.

The application relates to a kind of quantitative imaging methods of living cells based on digital holographic microscopic sequential displacement aberration correction, and belongs to the field of optical measurement, comprising: collecting three holograms by sequentially displacing living cells; obtaining three original phase maps by phase demodulation; obtaining total mask map; sequentially displacing phase map in reverse direction; performing difference calculation to obtain global phase system aberration difference data; obtaining local system aberration difference data by using total mask map; performing difference processing on Chebyshev polynomial to obtain local polynomial difference data by using total mask map; fitting global system aberration by calculating corresponding coefficients from difference data; subtracting global system aberration from three original phase maps to obtain phase map of living cells after aberration correction. The application realizes high-precision quantitative phase imaging of living cells while retaining high-frequency information, has excellent displacement distance robustness, does not need to be equipped with high-precision displacement mechanism, and greatly reduces the hardware cost of measurement system.

A composite material gas cylinder layering defect displacement prediction method based on deep learning and laser shearing speckle interference comprises the following steps: constructing a training data set combining simulation data and experimental data, generating the simulation data based on a shearing speckle interference imaging principle, and combining the experimental data acquired by an experiment to predict the layering defect displacement of a composite material gas cylinder. Constructing a mixed data set containing a wrapped phase diagram and an out-of-plane displacement diagram; constructing a deep convolutional neural network fused with an attention mechanism, and extracting displacement features from high-frequency stripes: starting from an input layer, sequentially connecting an encoder path, a bottleneck layer, a decoder path and an output layer; constructing a composite loss function and training the network, and constructing a composite loss function comprising a pixel-level error constraint and a gradient consistency constraint; and utilizing the trained deep learning neural network to predict out-of-plane displacement response at the layering defect of the gas cylinder. According to the method, the problems of image distortion, data missing and the like caused by a traditional phase unwrapping algorithm are effectively solved, and the out-of-plane displacement field can be accurately, smoothly and continuously reconstructed.

A monolithic homodyne encoder is described herein. The monolithic homodyne encoder includes a diffractive optical slab. The diffractive optical slab includes a first side and a second side that are optically parallel to each other, a first set of phase maps on the first side of the diffractive optical slab that apply a spatial phase map to incoming light, and a second set of phase maps on the second side of the diffractive optical slab that directs the light to a component.

This application discloses a 3D imaging method and system based on structured light phase measurement, relating to the field of 3D imaging technology. The method includes: calibrating a structured light measurement system to obtain intrinsic and extrinsic parameters, and determining the effective measurement depth range and the corresponding effective absolute phase interval; controlling a projector to project a preset sinusoidal fringe pattern onto the measured scene, acquiring a deformed fringe image modulated by the surface of the measured object, and obtaining a wrapping phase map; calculating the initial fringe order of each pixel based on the effective measurement depth range using a frequency domain order-based fringe order no-neighborhood solution algorithm; performing no-neighborhood verification and error correction on the initial fringe order based on the effective absolute phase interval using an order self-verification and error correction algorithm to obtain the final fringe order; and calculating the absolute phase map of the entire field of view based on the wrapping phase map and the final fringe order, and converting the point cloud data. This application aims to solve the technical problem of existing spatial phase unfolding techniques relying on the continuity of adjacent pixels.

The application belongs to the technical field of optical three-dimensional measurement, and discloses a two-division iteration sub-pixel matching method and system for phase structured light three-dimensional measurement, which comprises the following steps: obtaining a phase map; performing legality marking and pixel-level initial matching on the phase map; determining a sub-pixel search area based on the pixel-level initial matching; and performing sub-pixel matching point search based on the sub-pixel search area by using a two-division iteration method to obtain a sub-pixel matching point. The application can improve the precision of binocular matching in phase structured light three-dimensional measurement, thereby improving the precision of three-dimensional reconstruction.

The invention discloses a multi-focus composite Fresnel phase diagram rapid generation and power equalization method and system for one-to-many free space laser communication. According to the method, aiming at a scene in which a plurality of user targets are located at different directional angles and different propagation distances, a focusing + directional single-beam phase is constructed for each target on the basis of analyzing a Fresnel zone lens phase and a linear tilt phase, and the phase is taken after complex field superposition is performed according to a preset power weight, so that the target target is obtained. A composite phase diagram for a phase-type spatial light modulator (SLM) is directly obtained. The power weight is preset according to a link budget or a task demand so as to realize on-demand distribution and equalization of multi-beam output power; and meanwhile, fixed phase bias can be introduced to each beam to suppress inter-beam interference fringes. According to the method, frame-by-frame iterative solution is not needed, the calculation complexity is low, and high-frame-rate and low-delay online updating is easy to realize.

The invention discloses a cell hologram automatic focusing and aberration compensation phase reconstruction method based on deep learning, and the method comprises the steps: obtaining a to-be-processed off-axis digital hologram of a cell sample based on an off-axis digital holographic microscopy system, and carrying out the preprocessing of an original hologram, and enhancing the data size; processing the holograms in batches by using a phase reconstruction method considering aberration compensation to generate corresponding phase diagrams, and forming a ''hologram-phase diagram'' image pair data set for model training; the image pair data set is used for training a pix2pix network model, the input of the model is a cell hologram, and the output of the model is a focusing phase diagram; according to the invention, automatic focusing and phase reconstruction can be simultaneously realized for a single hologram, a clear and distortionless in-focus phase diagram is directly output, the problem that only an object in a specific distance range can be clearly imaged is solved, and the method is suitable for cell observation, label-free pathological detection and dynamic analysis of living cells in the field of biomedicine.

This invention discloses a method and system for de-flattening preprocessing, belonging to the field of radar imaging. The method includes: acquiring a main radar image and a secondary radar image, each containing several main image scattering points and several secondary image scattering points; calculating the secondary image scattering points corresponding to the main image scattering points to form several scattering point pairs; performing a flat-ground phase acquisition action to obtain an ideal flat-ground phase, thereby forming an ideal flat-ground phase map and completing the de-flattening preprocessing process. The flat-ground phase acquisition action includes: calculating the main image Doppler history and the secondary image Doppler history of the scattering point pairs; determining the main image focusing time that meets a preset time threshold to calculate the main image slant range, thereby determining the secondary image focusing time that meets the preset time threshold, and calculating the secondary image slant range based on the secondary image focusing time; and obtaining the ideal flat-ground phase of the scattering point pairs based on the main image slant range and the secondary image slant range. The de-flattening preprocessing method disclosed in this invention can effectively reduce the processing error of de-flattening preprocessing methods.

A system for training a machine learning algorithm to generate a plurality of ideal hologram phase correction maps includes a holographic head-up display (HUD) configured to display a plurality of duplicates of a graphic based on a hologram phase map. The system further includes a camera system configured to view each of the plurality of duplicates of the graphic. The system further includes a controller in electrical communication with the holographic HUD and the camera system. The controller is programmed to determine a plurality of ground-truth hologram phase correction maps using a genetic algorithm, the holographic HUD, and the camera system. The controller is further programmed to generate a training dataset including a plurality of images of the graphic and train the machine learning algorithm to generate the plurality of ideal hologram phase correction maps.

The application discloses a damage detection method based on a sparse wing array frequency modulation spectrum phase mapping method, and belongs to the technical field of crack detection. The method comprises the following steps: emitting a linear sweep wave and receiving a return wave; processing the return wave by using a spectrum phase mapping method. The main process of the spectrum phase mapping method comprises twin product transformation and Fourier transformation. The frequency difference between the sweep wave and the return wave can be obtained accurately, so that the distance from the damage to a sweep wave transceiving assembly can be calculated. The sweep wave transceiving assembly, namely a sparse wing array receiving device, is used for accurately positioning the damage. The device can firstly roughly determine the target direction, and then accurately position the damage crack according to a pair of receivers. The application can effectively improve the amplitude of the return wave signal, so that more accurate distance and position can be obtained, and the practicability is high.

The invention discloses a fatigue test crack detection method based on thermal imaging. In the periodic fatigue loading process, the surface temperature change of a sample is detected in real time through infrared thermal imaging, and an amplitude diagram and a phase diagram of weak temperature fluctuation are obtained through calculation; segmenting the sample through local phase consistency, prefabricating a gap and a background, and only performing subsequent analysis on a sample area so as to eliminate background interference; after the amplitude diagram is binarized, the boundary displacement influence is eliminated through a simple boundary displacement review strategy and by means of the boundary displacement direction and stress concentration point position relation, complex feature point matching and displacement estimation between images do not need to be conducted through the algorithm, the calculated amount is small, and reliability is high; the crack length is calculated according to the detected movement track of the crack tip feature point, the method does not depend on static crack features, the basic assumption that sample changes inevitably come from damage generation and development is utilized, and crack length evaluation is not affected even if wrong feature points are extracted through single-frame heat map analysis.

The present invention relates to a two-photon holographic optogenetic stimulation method, system, device, and medium based on wavefront correction. The method comprises: step S1, selecting a target neuron from two-photon imaging and obtaining a hologram corresponding to the three-dimensional spatial position of the target neuron; step S2, selecting a target region on the hologram requiring wavefront distortion correction for the target neuron, and performing wavefront distortion correction on the target neuron in the target region to obtain a phase map containing wavefront distortion information and position information; and step S3, optically exciting the target neuron based on the phase map containing wavefront distortion information and position information. Compared with existing technologies, the present invention achieves deep single-cell resolution excitation of more neurons with a large field of view, lower excitation power, and significantly improves the accuracy and safety of optogenetic stimulation imaging.

This application discloses a structured light encoding and decoding method based on polarization state modulation, relating to the field of 3D reconstruction technology. The method includes: controlling a projector to sequentially project a group of polarized structured light patterns onto the object under test, and controlling a polarization camera to synchronously acquire these patterns, obtaining a corresponding polarization image sequence; calculating the polarization angle of each camera pixel based on the polarization image sequence, obtaining a polarization angle map for each frame; for each camera pixel, calculating the wrapping phase based on the polarization angle map, obtaining a wrapping phase map for that frequency; obtaining an absolute phase map based on the wrapping phase map using a single-frequency absolute phase unfolding algorithm, establishing a mapping relationship between the column coordinates of camera pixels and projector pixels; and, based on pre-calibrated intrinsic and extrinsic parameters of the camera and projector, combined with the linear mapping relationship, calculating the 3D point cloud of the object under test through triangulation. This application aims to address the shortcomings of 3D reconstruction results being affected by the reflectivity of the object surface and ambient lighting.

Techniques for characterizing wafer bow are provided. In some embodiments, a method for determining wafer bow characteristics may involve projecting, using a projection device disposed in or on a portion of a semiconductor fabrication chamber, one or more fringe pattern images onto a surface of a wafer. The method may further involve capturing, using one or more camera devices, images representative of reflections of the one or more fringe pattern images from the surface of the wafer. The method may further involve generating an unwrapped phase map based on the captured images. The method may further involve generating a three-dimensional reconstruction of a surface of the wafer based on the unwrapped phase map using phase-measuring deflectometry.

The invention discloses a neural network enhanced wavefront sensing method and system based on a metasurface and double-helix PSF coding, and the method comprises the steps: loading a preset reference phase diagram and a to-be-measured phase diagram on unmodulated parallel light through a spatial light modulator, thereby generating a reference wavefront and a to-be-measured wavefront; mutually orthogonal double-helix phase distribution is generated by using the polarization multiplexing super-structure surface, and a reference double-helix point spread function image and a to-be-measured double-helix point spread function image are obtained; and outputting a phase distribution matrix of the wavefront to be measured by using the self-calibration dual-encoder neural network to realize synchronous reconstruction of the dual-channel wavefront. The method can realize high-resolution real-time wavefront measurement under single exposure, has high robustness and expandability, and is suitable for the fields of adaptive optics, polarization imaging, optical communication and the like.

The application discloses a kind of based on optimization's guiding filter image fusion change detection method and device, method includes: by extreme minimum scale difference operator, pixel value difference value is to the picture of same scene different phase, obtains difference map;Using the way of guiding filter, difference map is fused on global scale, to obtain the optimal difference map;Mean filter is used to phase map I1 and I2, and the base layer difference map corresponding to each difference map is obtained, and the optimized brightness saliency map F1 and F2 are obtained by pca fusion as the image of generating saliency map, according to the principle of maximum saliency to determine weight map;Weight map is regularized for double-scale difference map reconstruction, and the final difference map is obtained;In clustering segmentation stage, by introducing soft threshold function, the final difference map is further processed, to suppress existing abnormal noise.The device includes: processor and memory.

The present invention discloses a color Gray code encoding assisted phase unwrapping method and a three-dimensional imaging method and system using the method, belonging to the field of three-dimensional imaging technology. The method comprises the following steps: constructing two sets of colored sinusoidal stripe patterns of different frequencies, capturing the two sets of stripe patterns after projecting the scene to be measured; converting the stripe pattern from RGB format to HSV format, extracting the hue channel and performing Gray code decoding; extracting the hue channel from the RGB format stripes for intensity normalization, and then filling it into a single-channel image, calculating the wrapped phase using a phase shift formula, and then calculating the heterodyne phase of the stripe patterns of different frequencies by a multi-frequency heterodyne method, and performing a first unwrapping of the wrapped phase; using the Gray code decoding order to assist in unwrapping the first unwrapped phase map, thereby obtaining the final absolute phase. The present invention embeds Gray code encoding into different channels of the two sets of patterns, significantly reducing the number of patterns required and effectively improving measurement efficiency.

This invention discloses a method and apparatus for joint processing of 3D reconstruction, semantic segmentation, and depth estimation. First, the object is modulated using a sinusoidal grating fringe image, and a deformed fringe image containing the object's geometry and fringe coding information is acquired through imaging. Next, a semantic segmentation network is constructed to perform pixel-level classification of the fringe image, identifying different regions and generating a wrapping phase map; simultaneously, a depth estimation network is constructed to predict the depth map. Subsequently, the depth map is converted into a 3D point cloud using camera and projector parameters, and a coarse unwrapping phase is inversely solved. By comparing the coarse unwrapping phase with the wrapping phase predicted by the semantic segmentation network, a fringe order map is obtained, thus acquiring a precise unwrapping phase. Finally, the unwrapping phase is again converted into a 3D point cloud using parameters, achieving accurate 3D reconstruction of the measured object. This invention combines structured light technology, semantic segmentation, and depth estimation, improving the accuracy and efficiency of 3D reconstruction.

In a digital holographic wrapped phase aberration compensation method based on deep learning, a random Zernike polynomial coefficient and a corresponding wrapped phase map are generated by a computer and are respectively treated as a learning label and a network to train a neural network model. A digital holographic optical setup is built to record a hologram of a sample to be measured, the wrapped phase map is inputted into the trained neural network model after numerical reconstruction, and the Zernike polynomial coefficient is outputted to reconstruct a phase aberration distribution and to compensate complex amplitude in a spatial domain. Phase filtering and unwrapping are performed on the compensated wrapped phase map, and Zernike polynomial fitting based on background segmentation is performed on the unwrapped phase to compensate for residual aberration.

This invention discloses a phase-height mapping calibration method and apparatus in fringe projection, relating to the field of three-dimensional object contour measurement technology. The method includes: controlling a projector to project a set of phase-shifted sinusoidal fringe patterns onto a micromirror array with known height values; simultaneously triggering a camera to acquire fringe image sequences; performing phase shift calculations on the fringe image sequences to obtain a wrap-around phase map; constructing a global optimization model of absolute phase using the known height value of the micromirror array as an absolute constraint; solving for the absolute phase field corresponding to the height of the micromirror array; extracting the center coordinates, absolute phase values, and known height values ​​of each micromirror element; constructing a three-dimensional control point set; fitting the three-dimensional control point set; calculating the continuous model coefficient field; and forming a phase-height lookup table. This invention can significantly improve the real-time calculation efficiency of three-dimensional measurement, meeting the practical needs of high-precision, high-stability industrial three-dimensional shape measurement.

The invention relates to a method of MR imaging of an object (10) placed in an examination volume of an MR system (1). It is an object of the invention to enable an improved differentiation between abnormal / malignant tissue and tissue having a high water content in MR-EPT. The method of the invention comprises the following steps: generating MR signals by subjecting the object (10) to an imaging sequence comprising RF pulses and switched magnetic field gradients; acquiring the MR signals; reconstructing a magnitude MR image and a phase map from the MR signals for a given field of view within the object (10), which phase map is related to the spatial RF field distribution induced by the RF pulses within the field of view; deriving an electric conductivity map from the phase map, which electric conductivity map represents a measurement of the distribution of the electric conductivity within the field of view; deriving a further electric conductivity map from the magnitude MR image, which further electric conductivity map represents an estimation of the electric conductivity resulting from the distribution of water within the field of view; and identifying deviations of the two electric conductivity maps. Moreover, the invention relates to an MR system for carrying out this method as well as to a computer program to be run on an MR system.