21 results about "Two dimensional imaging" patented technology

A fundus imaging device has a fixation optical system, an OCT optical system, an imaging optical system, and a controller. The controller is configured to acquire a focus evaluation value based on a slit image formed by slit-shaped illumination light on a two-dimensional imaging element of the imaging optical system in a case where an optical scanner of the imaging optical system deflects in a predetermined direction. The controller is configured to perform diopter correction control of the OCT optical system by driving a first focus adjustment unit of the OCT optical system based on the focus evaluation value.

The application provides a prestressed steel bar nondestructive detection method and system based on ultrasonic imaging, relates to the technical field of prestressed concrete structure nondestructive detection, and is characterized in that a quasi-distributed ultrasonic transmitting-receiving array is arranged along both sides of the prestressed steel bar, each probe is sequentially excited and a multi-path echo sequence signal is synchronously collected, Hilbert-Huang transformation is performed on each path signal, a marginal spectrum is obtained through empirical mode decomposition and Hilbert spectrum integration, a barycentric frequency is extracted as a characteristic value which is highly sensitive to interface stiffness degradation, the barycentric frequencies of all paths are taken as projection data, an algebraic iterative reconstruction algorithm is used in combination with the spatial coordinates of the probes, a dispersion characteristic tomographic image of the measured section is reconstructed, a barycentric frequency variation curve is extracted from the image along the direction of the steel bar, and the area where a continuous shift occurs and the shift amount exceeds a threshold value is determined as an interface stiffness abnormal area, so that two-dimensional imaging diagnosis and spatial positioning of the interface state of the prestressed steel bar are realized.

This application relates to adjusting camera exposure for three-dimensional depth sensing and two-dimensional imaging. A method is disclosed, comprising: instructing, by a processing system of a distance sensor, a pattern projector of the distance sensor to project a pattern of light onto an object during a first timing frame; instructing, by the processing system, a camera of the distance sensor to acquire a first image of the object during the first timing frame, wherein the first image is acquired with an exposure time of the camera set to a first value; instructing, by the processing system, the pattern projector to project a pattern of light onto the object during a second timing frame after the first timing frame; instructing, by the processing system, the camera to acquire a second image of the object during the second timing frame, wherein the second image is acquired with the exposure time of the camera set to the first value; instructing, by the processing system, an illumination source of the distance sensor to illuminate the object during a third timing frame after the second timing frame; and instructing, by the processing system, the camera to acquire a third image of the object during the third timing frame, wherein the third image is acquired with the exposure time of the camera set to the first value.

Surgical planning based on a three-dimensional (3D) model includes obtaining a 3D model of an anatomical region, wherein the anatomical region includes the patient's anatomical features; identifying at least one deformity, wherein the at least one deformity is identified with respect to a target anatomical value of the patient's anatomical features, wherein the target anatomical value includes a desired range into which the anatomical measurement should fall; and using the anatomical measurement, determining at least one planar correction to be made to at least one anatomical structure of the patient. Generating a 3D model using two-dimensional (2D) imaging data may include performing anatomical context processing, which includes annotating the model, contours, edges, or surfaces of the anatomical structure, as well as performing 2D-to-3D reconstruction to optimize the orientation, placement, and scale of the 3D digital volume modeling the anatomical structure, resulting in a 3D anatomical representation of the anatomical region as a 3D model.

This invention provides a method, system, and medium for three-dimensional positioning and displacement measurement that integrates microwave and vision technologies. The method includes: rigidly connecting at least one microwave sensor and at least one vision sensor as a joint sensing unit; establishing a spatial transformation relationship between the coordinate systems of the two sensors through calibration; fusing the target's radial distance and angle information provided by the microwave sensor with the target's two-dimensional imaging information provided by the vision sensor; and directly solving for the target's three-dimensional coordinates in the selected coordinate system using an optimization algorithm; further combining the high-precision one-dimensional displacement information from the microwave sensor with the two-dimensional displacement information from the vision sensor to reconstruct the target's complete displacement vector in three-dimensional space. This invention, through a compact heterogeneous sensor fusion architecture, effectively solves the problems of limited dimensionality of single-sensor modes, high cost of multi-sensor networking, system complexity, and poor engineering applicability, achieving high-precision, low-cost, and full-dimensional non-contact three-dimensional positioning and displacement measurement.

The application discloses a kind of fast high-resolution imaging methods based on vortex electromagnetic wave, which constructs the two-dimensional imaging model of pitch angle and azimuth angle based on concentric circular ring array, realizes low-rank decomposition to the received echo and observation matrix by means of spherical harmonics function, introduces orthogonal matching pursuit algorithm to the scattering point in observation plane for target reconstruction, so as to realize the two-dimensional joint imaging of radar target pitch angle and azimuth angle.The imaging mode of joint OMP algorithm and spherical harmonic decomposition proposed in the application can realize higher imaging resolution compared with the traditional generalized inverse solution mode, while greatly reducing the operation amount of imaging process, effectively saving calculation time.

This invention discloses a satellite target attitude estimation method based on geometric feature constraints in ISAR images, comprising the following steps: segmenting typical satellite components in sequential ISAR images using a Conv-LSTM network and extracting component scattering centers using an attribute scattering center model; estimating the direction and length of the satellite's main axis using Principal Component Analysis (PCA); extracting the axis features of the solar panels using DBSCAN clustering and L-shaped rectangle search algorithms; and finally, constructing a projection geometric model of the target from a 3D to a 2D ISAR imaging plane by combining radar line-of-sight information, establishing an optimization objective function, and solving for the satellite attitude angles using a particle swarm optimization algorithm. This invention fully integrates the spatiotemporal information of sequential images with the geometric constraints of the target, effectively overcoming the projection variation problem caused by target motion in ISAR imaging, achieving high-precision satellite attitude estimation, and possessing strong anti-interference capabilities and practical application value.

OF THE DISCLOSURE Provided is a method for coupling a hemispherical lens to a terahertz optoelectronic chip. First, a printed circuit board and a hemispherical lens are ultrasonically cleaned. Then, a flat side of the hemispherical lens is placed against a back side of the printed circuit board, and UV glue is applied at the junction and cured with a UV lamp. The printed circuit board and the hemispherical lens are fixed on a base. A two-dimensional imaging instrument is used to align a center hole of the terahertz optoelectronic chip with a center of the hemispherical lens. Finally, a chip mounter is used to complete the coupling of the terahertz optoelectronic chip and the hemispherical lens. The coupling method of this application can be used in a fabrication process of transmission or reception chips, with a high degree of standardization, good compatibility, and high repeatability, making it suitable for large-scale manufacturing. Figure 1

The present application belongs to the technical field of visual guidance robot positioning, and particularly relates to a robot positioning method based on gradient weighting correction under multi-view. The present application firstly obtains the camera internal parameter matrix of each vision unit and the three-dimensional space coordinates of target features through calibrating the image of a calibration board in a common field of view; then establishes the matrix conversion relationship and inverse solution equation between the three-dimensional space and the two-dimensional imaging plane, and gradually obtains the external parameter matrix of each auxiliary camera relative to the main camera under the same world coordinate system; then constructs a gradient weighting correction algorithm using the gradient amplitude and phase correlation between the image pairs, filters out the error caused by the too large camera offset angle, and is used for correcting the conversion matrix between the multi-view vision units; finally, the data is converted to the robot base coordinate system through a hand-eye calibration algorithm, and the robot precise positioning based on gradient weighting correction under multi-view is realized. The present application increases the stability and robustness of the multi-view visual guidance robot positioning.

The application particularly relates to a kind of near distance multi-target fast deformation monitoring methods based on small aperture MIMO radar, high azimuth resolution two-dimensional imaging of multiple azimuth adjacent targets is realized by discrete fourier transform combined with MUSIC algorithm, and accurate positioning of multi-target is completed;Secondly, the mutual interference between target side lobe is suppressed using APES filter, and based on the target distance and azimuth information obtained in the previous step, the accurate recovery of target phase is realized;Finally, the time difference interference method is used to accurately estimate the small deformation of target visual distance.The space smoothing (FBSS) idea is introduced into the two-dimensional imaging algorithm, which effectively suppresses the coherent signal interference and realizes high azimuth resolution two-dimensional imaging in complex deformation monitoring scene.

The application relates to a method for intercepting an effective imaging scene of large-oblique SAR imaging by radar technical indexes, and belongs to the technical field of large-oblique SAR imaging. According to technical index requirements of a radar signal processor, such as a signal bandwidth, a sampling rate, a pulse accumulation time and the like, which are set by a project, the following specific requirements are calculated: an imaging scene center distance, an imaging width and a resolution in a distance direction and an azimuth direction of an imaging scene in a ground plane, and the like; according to a conversion relationship of oblique plane ground plane coordinate axes, the following are calculated: a distance dimension point number and an azimuth direction pulse pressure accumulation point number of a two-dimensional imaging scene in an oblique plane, so that effective data in data recording is retained, redundant data is removed, time consumption of real-time processing of an imaging algorithm is shortened, and design requirements are met.

The application discloses a low-scattering processing method of a support device, which comprises the following steps: designing upper and lower low-scattering cover bodies according to the structural features of the support device, so as to respectively include the lower part and the upper part of the support device, reducing the scattering ability of the support device, determining the position of the low-weak scattering source of the support device through a target two-dimensional imaging technology, and then performing comprehensive processing of scattering source separation and filtering, so as to reduce the influence of the support device on target stealth test. The application has the advantages of simple structure, convenient preparation and installation, and suitability for various types of support devices including jacks; the low-weak scattering source can be determined and the scattering source can be separated, the accuracy of subsequent processing is improved, and the workload of filtering and other series of processing is reduced.

The application discloses a frequency selection based two-dimensional imaging method of vortex electromagnetic waves, and belongs to the technical field of radar imaging. The method of the application firstly obtains a preliminary pitch angle of a target through a direction of arrival estimation method; determines a best imaging frequency corresponding to the pitch angle, wherein the best imaging frequency refers to a vortex electromagnetic wave working frequency which enables a main lobe of a vortex electromagnetic wave beam under a maximum mode number to cover the pitch angle; and excites the vortex electromagnetic waves to perform distance-azimuth two-dimensional imaging on the target by taking the determined best imaging frequency as a working frequency. The application further discloses a frequency selection based two-dimensional imaging device of vortex electromagnetic waves. Compared with the prior art, the application can effectively solve the problem of resolution deterioration of targets at different pitches caused by the divergence of vortex electromagnetic wave beams, and the most ideal azimuth resolution can be achieved within different pitch ranges.

This invention relates to the field of quantitative identification technology for plastic particles, and discloses a method for quantitatively identifying polystyrene microplastic particles. The method includes real-time acquisition of images of particles during transmission, identification of the dominant target color, automatic switching of the imaging background to the color with the highest contrast based on the target color to enhance the visual distinguishability of dissimilar particles, simultaneous acquisition of the two-dimensional position information and three-dimensional height information of the particles, construction of a spatial state vector for each particle, identification of dissimilar particles (not the target color) based on color classification, assignment of unique identifiers to each particle, and tracking of the motion trajectory of the dissimilar particles using multiple consecutive frames of images. This invention achieves micron-level three-dimensional positioning in high-speed online scenarios, providing crucial depth information for subsequent trajectory prediction and layered counting, fundamentally solving the problem that traditional two-dimensional imaging cannot distinguish overlapping particles in upper and lower layers, thus laying the foundation for high-precision measurement.

The application discloses a space-based external emitter ground-based synthetic aperture radar far-field pseudo-polar imaging method. The method firstly performs Fourier transform on time-domain signals received by monitoring antennas and reference antennas at different positions, performs conjugate multiplication in the frequency domain, and obtains target echo signals; distance dimension and azimuth dimension of the signals are decoupled; Taylor expansion order is determined according to imaging accuracy and efficiency requirements, and redundant phase terms generated after decoupling are Taylor expanded; decoupled echo signals after compensation under different orders are respectively subjected to two-dimensional fast Fourier transform, so that distance compression and azimuth focusing results are obtained; the results of different orders are accumulated and summed, so that a pseudo-polar coordinate system image is obtained; finally, the pseudo-polar coordinate image is converted into a rectangular coordinate, and a two-dimensional imaging result is output. The application can effectively realize balance between imaging accuracy and efficiency of the space-based external emitter ground-based synthetic aperture radar, and quickly obtain a high-resolution SAR image.

The application provides an ultra-wideband impulse SAR standing wave suppression method and device, relates to the field of radars, and comprises the following steps: obtaining echo data through ultra-wideband impulse SAR scanning and performing data preprocessing; performing two-dimensional SAR imaging by using the preprocessed echo data to obtain a two-dimensional SAR image with a standing wave; selecting a mismatch frequency range according to a standing wave signal frequency model and actual antenna parameters, and removing in the distance spectrum of the two-dimensional SAR image; extrapolating the removed frequency components by using an energy-weighted least square method to obtain a complete distance spectrum; and transforming the obtained distance spectrum back to an image domain after a certain amplitude weighting to obtain a two-dimensional SAR image after standing wave suppression. The application discards mismatch frequency components in the distance spectrum of the two-dimensional SAR image, realizes the suppression of mismatch signal components, and solves the spectrum leakage and distance resolution loss caused by the removal of the frequency components through spectrum extrapolation.

The present disclosure provides a compact fingerprint and finger vein combined scanner comprising a cemented prism pair (1') with first prism block (3) and second prism block (2), selective interference coating (7) between the prism blocks that transmits red wavelength light and reflects near-infrared wavelength light at different incidence angles, red LED (4) illuminating finger placement surface (6) on the first prism block (3), at least one near-infrared LED (5) illuminating the finger placement surface (6), imaging lens system (8) comprising First imaging lens (8a) and Second imaging lens (8b) arranged in sequence receiving light from the cemented prism pair (1'), aperture filter (9) between the imaging lens system (8) and imaging detector (10) with wavelength-selective filter transmitting red wavelength light and absorbing near-infrared wavelength light and central opening transmitting both wavelengths, and two-dimensional imaging detector (10) receiving light through the imaging lens system (8) and aperture filter (9).

The present application belongs to synthetic aperture radar technical field, especially to a kind of GEO star ground bistatic SAR aperture optimization method and device based on resolution optimum, the specific process of this method is as follows: based on the resolution ellipse obtained by multiplying two main lobes when GEO star ground bistatic SAR two-dimensional imaging, construct resolution ellipse long axis model;Select core imaging area, according to ground plane range resolution and azimuth resolution, construct ground plane range and azimuth resolution mean model of core imaging area;Set the traversal step of trajectory, traverse to obtain the long axis of ellipse and resolution mean of full track section, select trajectory section that meets the requirement of set long axis of ellipse and resolution mean;Set two constraint conditions of core imaging area without blur and GEO star ground bistatic SAR visibility, complete imaging arc segment final selection using constraint condition, thus complete imaging aperture optimization based on double constraint joint screening.

The application provides a vortex electromagnetic wave three-dimensional imaging method based on a uniform symmetrical concentric circular array, and specifically comprises the following steps: S1, constructing a uniform concentric circular antenna array to obtain distance and azimuth angle information of a radar target in a spherical coordinate system; S2, obtaining azimuth and elevation angle information of the radar target in the spherical coordinate system; S3, constructing a uniform concentric circular antenna array-average linear antenna array hybrid array, and then optimizing the uniform concentric circular antenna array into a uniform symmetrical concentric circular antenna array; adopting a backward projection algorithm, distance and azimuth information [x, y] of the radar target in a rectangular coordinate system is obtained; and S4, performing correlation processing on the obtained two-dimensional imaging result of the radar target to obtain accurate three-dimensional imaging result of the target. The array elements can form a uniform linear array for observing the radar target in space, the array structure of the uniform symmetrical concentric circular array is further optimized by combining the characteristics of the backward projection algorithm, and the antenna complexity and the total number of array elements are effectively reduced.

A self-supervised 3D imaging method for multi-view SAR and ISAR with arbitrary observation geometry is proposed, comprising: acquiring observation geometric parameters and 2D imaging results from multiple views; constructing 2D projection relationships for each view based on the observation geometric parameters; acquiring the scattering parameter set of sampling points in the 3D sampling space corresponding to each view based on the implicit scattering field network constrained by geometric conditions and the 2D projection relationships; performing differentiable forward imaging based on the scattering parameter set and the 2D projection relationships to generate 2D predicted images for each view; constructing a multi-view consistency loss based on the 2D imaging results and 2D predicted images for each view; performing self-supervised iterative optimization of the implicit scattering field network based on the multi-view consistency loss until a preset iteration condition is met, and performing 3D scattering reconstruction based on the scattering parameter set to obtain the 3D scattering field reconstruction result. This method eliminates the need for 3D ground truth annotation, achieves stable 3D imaging, and improves adaptability.