359 results about "Spatial frequency" patented technology

The invention provides a power cable test data identification method and system, and the method comprises the steps: obtaining an electrical signal sequence of a power cable under a plurality of preset test condition combinations, carrying out the space-frequency joint feature decomposition of the electrical signal sequence, and constructing a three-dimensional time-frequency data body comprising a space position, a time sequence and a frequency feature; constructing a dynamic phase space on the basis, reconstructing a state trajectory of each physical segment, calculating a fractal dimension spectrum and a nonlinear divergence coefficient set of the trajectory, and generating a defect evolution characteristic tensor; inputting the defect into a spatio-temporal chaotic mapping network, aligning characteristic evolution paths of different physical segments, and constructing a defect propagation spatio-temporal atlas; and analyzing the fault development trend of each physical segment in the time dimension and the defect diffusion path of each physical segment in the space dimension, and outputting an identification result containing a defect type evolution probability sequence and a three-dimensional position offset field. According to the invention, a more accurate and comprehensive basis is provided for state evaluation and maintenance of the power cable.

The invention discloses a real haze image defogging method based on a haze degradation model. The method comprises the following steps: constructing a haze degradation model fusing multiple scattering effects and multiple image degradation factors; using the haze degradation model to construct a training data set including the clear image and the corresponding pseudo haze image; constructing a defogging network for a real haze scene; training the defogging network by adopting the training data set until a preset loss function is converged; and inputting a to-be-defogged image into the trained defogging network to obtain a defogging result. According to the haze degradation model constructed by the invention, the difference between a synthetic domain and a real domain is effectively relieved; a designed space-frequency hybrid module improves the adaptability of the model to complex degradation characteristics; the prior-guided feed-forward network fully excavates and fuses dark channel prior information, and the sensing and modeling capability of the model to the haze area is effectively enhanced.

The invention relates to the technical field of spectrum detection, and discloses a quality control method for traditional Chinese medicine capsules, which comprises the following steps: continuously scanning by using a micro light spot probe during capsule movement to obtain a spatial spectrum response sequence; performing adjacent micro-area differential operation on the sequence, and filtering a shell background and retaining a particle scattering signal by utilizing a microstructure difference between a capsule shell continuous film and a powder content discrete accumulation; according to the method, a traditional path of a shell standard model is established, through a spatial frequency domain decoupling mechanism, reference errors caused by batch drifting of shell physical attributes are avoided, and the detection sensitivity of trace component fluctuation and foreign matter mixing is improved.

The invention discloses a method and a system for identifying an anti-counterfeit label. The method comprises the following steps: acquiring spectral response characteristics of the anti-counterfeit label to be identified through a multiband optical sensor; extracting a dynamic coding area and a base material characteristic area in the spectral response characteristics, wherein the dynamic coding area comprises topological distribution information of a programmable encryption particle array; processing the topological distribution information of the dynamic coding region through a feature compression algorithm to generate a first verification factor, and extracting a spatial frequency feature of the base material feature region as a second verification factor; and uploading the first verification factor and the second verification factor to a cloud verification platform through a secure communication protocol, wherein the cloud verification platform is internally provided with a dynamic spectral feature library and a physical feature association model. According to the invention, through a double-engine architecture of programmable dynamic target and environment adaptive verification, the problems of static replicability and environment vulnerability of physical anti-counterfeiting are solved, and collaborative rise of anti-counterfeiting strength and use reliability is realized.

The embodiment of the invention provides a beam coverage method and device of an antenna array, equipment and a storage medium. The method comprises the steps of determining an initial beam coverage area; determining a reference center position in the initial beam coverage area, and constructing a rectangular window according to the maximum spatial frequency deviation of the initial beam coverage area relative to the reference center position; constructing a rectangular window function; obtaining a space beam forming gain function and determining a first relation function between the beam forming weight vector and the beam forming vector; inverse Fourier transform is carried out according to the spatial beam forming gain function to obtain a beam forming weight vector function, and a second relation function is determined based on the rectangular window function and the beam forming weight vector function; and calculating a target beam forming vector of the antenna array in combination with the first relation function and the second relation function, and controlling the antenna array to perform signal coverage on the initial beam coverage area according to the target beam forming vector. In this way, the real-time performance of beam configuration of the antenna array can be improved.

The invention provides a cable water-blocking buffer layer ablation degree detection method. The method comprises the following steps: acquiring a visible light image and an infrared image of a water-blocking buffer layer of a cable; performing weighted fusion on the visible light image and the infrared image to obtain a target image; performing multi-scale decomposition on the target image to obtain a plurality of spatial frequency images corresponding to the target image, the multi-scale decomposition being decomposition of the image into different spatial frequencies; and under the condition that the spatial frequency corresponding to the at least one spatial frequency image is greater than a preset frequency threshold, determining the ablation of the water-blocking buffer layer of the cable, and determining the ablation degree of the water-blocking buffer layer of the cable according to the target image. According to the scheme, the problem that the ablation degree cannot be accurately evaluated by adopting single-dimensional data in the prior art is solved.

The invention discloses an SAR (Synthetic Aperture Radar) image MTF (Modulation Transfer Function) quality evaluation method and system based on a natural scene edge, and the method comprises the steps: building a selection standard system for automatic edge screening of a natural scene SAR image, and determining a high-contrast linear edge according to the standard system; automatically detecting a high-contrast linear edge in the natural scene, and intercepting a region of interest for subsequent calculation based on the position of the linear edge; gray level distribution is extracted in the normal direction of the linear edge, and an edge spread function is constructed and used for describing gray level transition response of the imaging system in the edge area; carrying out normalization and smoothing processing on the edge spread function, and carrying out spatial domain first-order differential calculation to obtain a line spread function; and performing fast Fourier transform on the line spread function to obtain a modulation degree transfer function curve, and representing the detail transfer capability of the system under different spatial frequencies. According to the method, the imaging quality of the SAR image of the natural scene can be automatically, accurately and quantitatively evaluated under the condition that manual field arrangement is not needed.

The invention relates to the technical field of numerical control machining measurement and correction, and discloses a machining surface correction method for a numerical control milling center. The method comprises the steps of establishing an original point cloud of a processing surface and extracting a feature structure; analyzing each feature structure to form a structured description list; inputting the list into a geometric growth model, and generating a virtual feature structure set according to rule iterative evolution; extracting and rasterizing the contour and the height field, carrying out registration fusion with a reference plane equation, and carrying out variation calculation to obtain a smooth middle geometric surface; performing adaptive resampling on the intermediate surface to generate an intermediate point cloud; and finally, according to the spatial frequency distribution of a topological residual field formed by the difference between the original point cloud and the intermediate point cloud, adaptively determining a weight, and carrying out weighted mixing on the original point cloud and the intermediate point cloud to generate an optimized surface point cloud. According to the method, intelligent evolution of the machined surface features and frequency domain self-adaptive data fusion are achieved, and the correction machining precision and the surface forming quality are improved.

The invention discloses an ISAR image ship coarseness identification method and system based on scattering feature estimation, and relates to the technical field of target identification, and the method comprises the steps: constructing and training a target identification model; the target recognition model comprises a small grazing angle image feature enhancement module based on scattering characteristic estimation, a feature extraction fusion module based on motion attitude decoupling and a full connection module; the small grazing angle image feature enhancement module comprises a scattering center parameter estimation module, a complex waveform feature extraction module and a physical data feature fusion module; the feature extraction fusion module comprises a spatial frequency domain attitude mode representation module, an attitude adaptive deformation convolution module and a frequency domain space double-attention fusion module; obtaining an ISAR image of a to-be-identified marine ship; and inputting a to-be-identified marine ship ISAR image into the trained target identification model for ship type identification. According to the invention, the identification precision of the ship type under the conditions of small grazing angle and complex motion imaging is improved.

The utility model provides an optical path difference regulation structure lens, and relates to the field of optical lenses, the lens comprises a lens body and a lens part, the lens body comprises a convex surface and a concave surface opposite to each other; the lens part is adjacent to the concave surface of the lens body, the lens part comprises a micro-lens array, and the micro-lens array comprises a plurality of micro-lenses which are sequentially arranged to form an ultra-microstructure area; the micro lens is of a nanoscale diffraction structure and has the effective haze not exceeding 15% so as to reduce the spatial frequency and the imaging degree of incident light in the ultra-microstructure area. According to the invention, multiple functions of defocus optimization design, contrast control, spatial frequency modulation and the like are integrated; the effective defocusing amount of the ultrastructure is larger, and the ultra-low disturbance amount is achieved; and the haze of the micro lens is controlled at a nano level, so that a high-fidelity optical effect can be provided.

The invention discloses a micro-plastic detection model construction method, a detection method, equipment and a medium. The method comprises the following steps: constructing a micro-plastic detection model; the feature extraction module is used for extracting feature maps of various different scales from an input image, performing feature fusion and feature enhancement on the feature maps of various different scales, and then identifying micro-plastic information from the feature maps and outputting the micro-plastic information; the model comprises an MFM module, an FS-C3k2 module and a GSConvE module; the MFM module is used for carrying out feature fusion on feature maps of different scales; the FS-C3k2 module is used for dividing an input feature map into two channels, one channel is spliced with the other channel after space-frequency feature extraction and feature enhancement, and a first enhanced feature map is obtained; the GSConvE module is used for performing deep feature enhancement on the first enhanced feature map; and taking model loss function minimization as a target training model. According to the invention, the precision and accuracy of micro-plastic detection are improved.

The application relates to a kind of diffractive optical element beam shaping methods based on spatial frequency filtering, obtain incident light beam, based on the homogenization light beam of preset, obtain corresponding geometric analytical phase distribution;Adjust the homogenization light beam to rectangular flat-top light beam, the phase correction processing of obtained geometric analytical phase;Based on spatial frequency filtering method processing the geometric analytical phase after phase correction, get the light field regulation and control distribution requirement after processing, the light field regulation and control distribution requirement after processing has phase and amplitude regulation and control requirement simultaneously;Design diffractive optical element, make it realize the light field regulation and control distribution requirement required, and utilize the diffractive optical element to realize the incident light beam shaping as the rectangular flat-top light beam.The application can realize the light beam homogenization effect of high uniformity, edge sharp and high diffraction efficiency, and obtain wide application prospect in laser welding, photoetching and biomedical and other aspects.

The invention belongs to the technical field of computer vision and computer graphics, and discloses a multi-view three-dimensional reconstruction method and device based on cross-domain feature fusion and a medium, and the method comprises the steps: carrying out the cross-feature-domain coding of an initial feature token generated by a multi-view image, according to the coding, characteristics are decomposed into low-frequency components and high-frequency components through dual-tree complex wavelet transform, amplitude modulation is carried out on the high-frequency components to enhance details, and space-frequency fusion characteristics are generated; variance embedding weighted combination is carried out on the multi-view space-frequency fusion features, the combination generates a weight by calculating the variance of each feature token, adaptive weighted clustering is carried out based on the weight, and fused multi-view features are generated; and performing three-source attention decoding on the fused features, and performing cross-domain attention calculation and up-sampling by taking static embedding as query, taking the space-frequency fused features as keys and taking the fused multi-view features as values, thereby finally generating a three-dimensional voxel reconstruction result of the target object.

The invention belongs to the technical field of ultra-precise angle measurement, and discloses a three-dimensional angle measurement device and method based on wavefront interference fringes. According to the invention, two wavefront interference light spots are generated by using two paths of detection laser in a single interference measuring head with only a single coordinate reference, the spatial frequencies of respective fringe images in the horizontal and vertical directions are respectively calculated, and simultaneous decoupling is carried out so as to accurately measure the pitching, deflection and rolling angle deviations of the reflector. According to the three-dimensional angle measurement device, point-to-point three-dimensional angle measurement can be achieved, the measurement resolution is high, the measurement result can be directly traced to the laser wavelength, and the requirement of high-end equipment for ultra-precise three-dimensional angle measurement is met.

The invention relates to the technical field of nondestructive testing, and discloses a wind power casting nondestructive testing method and system, and the method comprises the steps: obtaining three-dimensional surface point cloud data of a to-be-tested wind power casting, employing a sound ray tracking algorithm to calculate a sound path distance and a propagation angle between each imaging point and each array element in an imaging grid, and generating a focusing rule; performing full-matrix data acquisition to obtain an original time domain signal, performing wavelet packet decomposition on the original time domain signal, and determining the peak kurtosis of the original time domain signal; carrying out weighted coherent superposition on any imaging point in the imaging grid based on a focusing rule and an original time domain signal, and reconstructing an image; and identifying a defect indication area in the reconstructed image, calculating an average spatial frequency gradient, determining the number of iterations of a deconvolution algorithm, performing deconvolution processing on the image of the defect indication area, and determining the contour and size of the defect. According to the method, the defect signal can be effectively enhanced, the noise interference is inhibited, and the accuracy of the defect detection result of the wind power casting is improved.

The invention discloses a skin lesion segmentation method and system based on dual-path perception multi-stage fusion, and relates to the technical field of medical image processing, and the method comprises the steps: carrying out the block division of a skin image, inputting into an encoder, and filtering a key lesion region through employing a region sparse attention mechanism; performing down-sampling on the feature map by using a block merging operation, and constructing a multi-scale feature pyramid; skin image features are processed by using a dual-path sensing multi-stage fusion network, deepest features generated by an encoder are processed by a spatial frequency dual-path cascade sensing module, and two-stage space-frequency collaborative optimization is executed; the method comprises the following steps: establishing jump connection between an encoder and a corresponding decoder through a space channel double-path parallel sensing module, recovering spatial resolution through block expansion operation in combination with modulated encoder characteristics, and generating a pixel-level lesion probability graph. According to the method, the context sensing capability across the space domain and the frequency domain is remarkably enhanced, and an accurate and detailed skin lesion segmentation result is obtained.

The invention belongs to the technical field of visual health, and relates to a myopia prevention and control method and system based on spatial frequency monitoring and adjustment and application. The method comprises the following steps: processing an environment image of a to-be-monitored area to obtain a spectrogram, taking a zero frequency component of the spectrogram as a center, and radially averaging frequency spectrums in all directions to obtain a curve of amplitude changing along with spatial frequency; carrying out linear fitting on the curve of the amplitude changing along with the spatial frequency under a double logarithmic coordinate to obtain a fitting straight line; obtaining a spatial frequency characteristic index of the to-be-monitored area based on the slope of the fitting straight line; and comparing the spatial frequency characteristic index with a preset spatial frequency threshold value, and if the spatial frequency characteristic index is smaller than the preset spatial frequency threshold value, generating a texture pattern containing high-frequency information and projecting the texture pattern to the to-be-monitored area. According to the application, the spatial frequency is taken as a direct adjustment index, and myopia prevention and control are more accurate and effective by monitoring and adjusting the spatial frequency.

The invention discloses a graph enhancement-based rolling bearing small sample fault diagnosis method, which comprises the following steps of: firstly, mapping a time-frequency image into a weighted undirected graph capable of accurately describing local texture and global semantic association through a self-adaptive dynamic graph construction strategy by calculating a pixel neighborhood variance and a global expectation thereof and dynamically generating a connection threshold value; the space-frequency dependency relationship between the pixels is explicitly coded; a graph feature enhancement residual block is designed in the diffusion denoising process, and the feature expression of a diffusion model in the denoising process is enhanced by cooperating with the local perception of the convolutional neural network and the global reasoning ability of the graph neural network by using the gating fusion and attention mechanism. And finally, the modules are integrated in the graph enhanced U-shaped network, so that high-quality and high-diversity fault sample generation is realized. Experiments show that the method significantly improves sample diversity and diagnosis accuracy on two bearing data sets, and provides a new approach for intelligent fault diagnosis under small sample conditions.

The invention belongs to the technical field of medical image processing, and discloses an extreme illumination-oriented visible light and infrared image fusion method, system and device based on text-guided spatial frequency domain interaction, and a medium. The text prompt corresponds to the visible light image, and the text prompt corresponds to the infrared image; constructing an image fusion network, wherein the image fusion network comprises two image encoders, two text encoders, a plurality of fusion modules and a decoder; and based on the mixed loss function, training the image fusion network by using the data set, and realizing fusion of the visible light image and the infrared image through the trained image fusion network. According to the method and the device, the problems of semantic difference between the text and the visual features and insufficient modal complementary information utilization are solved, and efficient complementation and semantic enhancement of the multi-modal features can be realized.

A mechanism for processing one or more laser speckle images. A spatial frequency transform is used to transform the one or more laser speckle images into spatial frequency data. The spatial frequency data is used to define a plurality of blood velocity indicators, which each indicate an amount of blood moving at a particular velocity within an illuminated region of interest.

The invention provides an intelligent feedback control glass outer diameter screening method, which comprises the following steps: collecting the reflected light intensity and refracted light angle of the surface of glass, analyzing the spatial frequency distribution characteristics of local scattering intensity, identifying the surface microcrack distribution mode and quantifying the defect depth change; distinguishing real structure defects and surface tiny scratches, and obtaining defect boundary sharpness and defect size distribution parameters; based on the denoised signal data, dynamic evolution characteristics of defect distribution are extracted, and a space-time incidence matrix containing light intensity spatial frequency periodicity and angle deviation periodicity is constructed; carrying out weight redistribution on the space-time incidence matrix by utilizing a dynamic weight distribution coefficient, and carrying out weighted fusion on local scattering intensity information and refracted light phase difference information to generate a fused feature signal; based on the space-time characteristic parameters of the fused characteristic signals, the influence of sudden drop of reflected light intensity and signal distortion on outer diameter judgment is reduced to the maximum extent, and optimized outer diameter judgment signals are output.

The invention discloses an infrared target tracking method and system based on space-frequency dual-domain interactive fusion. The tracking method comprises the following steps: performing multi-direction decomposition on an original search image and an original template image to obtain a transverse high-frequency image and a longitudinal high-frequency image; performing adaptive foreground mask on a high-frequency image of the original template image to obtain an adaptive mask image; performing point-by-point multiplication on the original search image and the corresponding high-frequency image to obtain a first search image; performing feature extraction on the first search image and the target area mask image to obtain spatial domain features and frequency domain features of the search image and the template image; performing dual-domain interactive fusion on the spatial domain features and the frequency domain features to generate dual-domain fusion features of the search image and the template image; and performing classification and regression according to the obtained double-domain fusion features to obtain a target bounding box information prediction result in the search image. According to the method, under the condition that the structure prior is not clear, accurate tracking of the target can be achieved, and the tracking effect is remarkably improved.

The invention discloses an edge-guided self-adaptive fusion remote sensing image change detection method based on spatial frequency domain interaction. The method comprises the following steps: preparing data of front and rear remote sensing images and real change labels; preprocessing based on the previous and later remote sensing images and labels to obtain a standardized data set; an edge-guided adaptive fusion network based on spatial frequency domain interaction is constructed, feature enhancement is carried out through a spatial and frequency double-branch structure, and an adaptive orthogonal fusion module is designed to carry out multi-construction interactive fusion on double-time features. Introducing an edge driving wavelet reconstructor as an auxiliary supervision branch to guide the feature change region edge modeling capability; and finally, a high-precision change prediction map is generated by inputting a double-time-phase remote sensing image. The method aims at solving the problems that edge prediction details are insufficient and background noise is difficult to restrain in a traditional change detection technology, the detection performance is effectively improved, the advanced change detection performance is shown on a data set, and the method has high competitiveness and practical value.

A base station testing system provides, for display, a graphical user interface (GUI) associated with facilitating testing of a base station by the base station testing system. The GUI includes one or more selectable indicators respectively associated with one or more modules of the GUI. The base station testing system obtains, based on providing the GUI, information indicating selection of a selectable indicator that is associated with analysis of beam patterns associated with the base station and thereby identifies a beam pattern analysis module that is associated with the selectable indicator. The base station testing system provides, for display, in a window of the GUI, information associated with the beam pattern analysis module, wherein the information associated with the beam pattern analysis module includes spatial frequency domain beam pattern analysis information associated with the base station.

A method for generating a digital fabric tile. A step of the method includes, in a processor, determining a fundamental spatial frequency in an image of the fabric in each of two orthogonal directions. A step of the method includes, in the processor, determining a plurality of weave vectors for the image of the fabric. A step of the method includes, forming the tile using the fundamental spatial frequency in each of the two orthogonal directions and the plurality of weave vectors.

The application provides a curved surface optical element surface defect scattering detection method and system, which comprises the following steps: setting a pre-focusing incident light beam in a detection light path, so that the incident light beam forms a virtual object point behind the curved surface optical element; adjusting the distance from the virtual object point to the vertex of the curved surface to satisfy a conjugate relationship with the distance from the detector to the vertex of the curved surface; discretizing the illuminated local curved surface region into an array of micro surface elements; calculating the projection of the unit vector of the scattered light and the unit vector of the incident light on the local tangent plane of each micro surface element to establish a local spatial frequency mapping relationship; performing surface-detector geometric modeling, micro surface BRDF calculation, radiation transmission and irradiance calculation of the scattered light field, constructing a curved surface scattering physical model and reconstructing the irradiance distribution on the detector target surface; performing total integral scattering processing on the irradiance distribution to identify defects, extracting the power spectral density of the defect region to obtain five frequency domain characteristic values, and inputting the five frequency domain characteristic values into a machine learning classifier for defect classification.

The application discloses a space-time-frequency wave number domain synchronous extrusion superimposed dense channel reservoir characterization method, which comprises the following steps: S1, inputting original seismic data s(t, x) to be analyzed, wherein x is the number of channels, and t is time; S2, obtaining short-time Fourier transform V2(t, x, omega, k) of the signal by using a Gaussian window function g(t, x), wherein omega is frequency, and k is wave number; S3, calculating an instantaneous frequency and an instantaneous wave number estimation of the signal according to S2; S4, defining an extrusion operator TDSTO according to S3; S5, constructing a space-time-frequency wave number domain synchronous extrusion transform characterization method TDSST(t, omega, x, k) according to the extrusion principle; S6, fixing the wave number by maximizing the energy of TDSST, so as to obtain a TDSST time-space-frequency domain three-dimensional data body TDSST(t, x, omega, k(t, x, omega)); and S7, performing feature extraction of frequency f0 in S6, so as to obtain a single-frequency profile to characterize the morphological structure characteristics of a complex superimposed dense channel sandstone reservoir. The application can provide a space-time reservoir morphological characterization method considering the lateral characteristics of a complex superimposed dense channel sandstone.

The invention discloses a dynamic cross-domain general ship detection method based on edge wavelet guidance, which is suitable for optical and SAR remote sensing images. By constructing a unified detection framework, complexity and low efficiency caused by two independent detection models in a traditional method are avoided. Firstly, an edge wavelet guidance attention module adopts a spatial frequency double-decoupling mechanism; wavelet transformation high-frequency gating is utilized on the edge guiding feature, structural representation with the consistent cross-modal height is generated, and the modal gap problem is fundamentally solved. Secondly, the self-adaptive dynamic expansion convolution module solves the problem of scale distribution difference; a dynamic tanh activation function is introduced as a learnable dynamic calibrator and is responsible for adaptively aligning multi-scale feature distribution of different modals. And finally, an ensemble structure attention enhancement module explicitly applies geometric priori constraint to a self-attention mechanism, so that the anti-interference capability is enhanced, and the network attention is guided to only pay attention to the target form irrelevant to the mode. According to the method, complexity and low efficiency caused by two independent detection models in a traditional method can be avoided, and the application effect of a detection system in a complex dynamic environment can be improved.

This application discloses a method and system for synchronous testing of metasurface grating waveguide performance, relating to the field of metasurface grating technology. The method includes polarization state modulation and spatial frequency encoding of multi-wavelength incident beams to obtain a modulated incident light field; coupling this modulated incident light field into the metasurface grating waveguide under test, which then undergoes total internal reflection to form the outgoing light field; acquiring a raw dataset of the entire light field, including Stokes polarization images and spatial spectrum images corresponding to each wavelength of the outgoing beam; calculating the total internal reflection hop count based on the Stokes polarization image; calculating the spatial step size offset based on the spatial spectrum image; and establishing a mapping relationship between the image pixel coordinates of the raw dataset and the internal physical regions of the metasurface grating waveguide under test to obtain local diffraction efficiency distribution data. This application solves the problem that traditional outgoing end intensity testing is difficult to trace to local defects inside the waveguide, achieving synchronous, high-precision quantitative characterization of local diffraction efficiency across multiple wavelengths.