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34 results about "Fractional differential" patented technology
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Texture force touch sensing method based on single image fractional order processing
InactiveCN104050683AEnhanced Edge ProfilesEnhanced detail texturesInput/output for user-computer interactionImage enhancementDamping factorPattern recognition
The invention discloses a texture force touch sensing method based on single image fractional order processing. The method includes the steps that a fractional differential algorithm is utilized, the order gamma of the fractional differential algorithm is adjusted dynamically, an enhanced texture image is obtained, original image texture information is extracted from the enhanced texture image, and multi-scale analysis of the detail texture and the edge contour of different rates of gray level changes is achieved from the point of image airspace gray level change features; force touch rendering is carried out on the virtual surface texture, and tangential force frictional damping coefficients of a force touch sensing model are controlled on the basis of gradient vector distribution of the enhanced texture image; obtained resultant force is calculated and fed back to an operator through a hand controller. By the utilization of sensibility of fractional differential to detail information, the sense of reality of texture force touch sensing is enhanced by manually selecting orders, extracting texture information in a two-dimensional image signal from different scales and converting the texture information into frictional damping control.
Owner:SOUTHEAST UNIV
Method for removing cosmic rays in charge-coupled device (CCD) astronomic image
InactiveCN102881003AIncrease the amount of informationQuality improvementImage enhancementImage analysisFractional differentialComputer vision
The invention discloses a method for removing cosmic rays in a charge-coupled device (CCD) astronomic image. The method comprises the following steps of: (1) performing sub-sampling on an original image I to obtain a sub-sampled image; (2) improving a Laplacian operator, amplifying the sub-sampled image, performing convolution operation on the amplified sub-sampled image and the improved Laplacian operator, removing a negative value, and recovering an original size to obtain a Laplacian image L'; (3) identifying cosmic rays in the Laplacian image L'; (4) removing the cosmic rays in the Laplacian image L'; and (5) performing image edge enhancement processing on the image in which the cosmic rays are removed by utilizing a fractional differential normalized Tiansi operator. According to the method, the identification rate of the cosmic rays is greatly increased, a part influenced by the cosmic rays in a star can be maximally retained, and the processing quality of the image is improved.
Owner:JINAN UNIVERSITY
Image edge detection method based on fractional order partial differential
InactiveCN103247047AEasy extractionEasy to detectImage analysisPattern recognitionFractional differential
The invention discloses an image edge detection method based on fractional order partial differential, which comprises the following steps: the Sobel operator and a 3*3 pixel neighborhood with the gray-scale function of F (x, y) are subjected to convolution; the convolution sum is subjected to central difference to obtain an integral order differential expression; the integral order differential expression is replaced by a v order differential expression; based on definition of fractional differential, first three items of the fractional differential expression of a digital image substitute values in the v order differential expression; and different results can be obtained through regulation parameter, namely the differential order v. The method can satisfactorily extract edge contour information, has an excellent effect on texture detail detection, is superior to conventional edge detection methods, and satisfactorily achieves the purpose of image edge detection.
Owner:CHONGQING JIAOTONG UNIVERSITY
Wavelet domain-based method for weighting fractional differential image digital watermark
InactiveCN102129655AOvercoming cracking problemsImprove securityImage data processing detailsFractional differentialImaging processing
The invention provides a wavelet domain-based method for weighting a fractional differential image digital watermark, which mainly solves the problem that the high-frequency coefficient of an image undergoing wavelet decomposition is susceptible to extraneous noises and conventional image processing. The method comprises the implementation steps of: doing two different orders of differentials for a sinusoidal signal by utilizing a fractional order Cauchy formula; respectively carrying out discrete sampling and superposing by utilizing a given weight to generate a pseudorandom sequence and adding the pseudorandom sequence with a watermark pixel value to realize watermark scrambling; carrying out two-stage decomposition on a carrier image by utilizing a Haar wavelet and embedding the scrambled watermark information in the carrier image through the exchanged and decomposed high-frequency coefficient; and through comparing the high-frequency coefficient undergoing the two-stage decomposition by utilizing the Haar wavelet, extracting the scrambled watermark and subtracting the pseudorandom sequence to realize watermark recovery. The method provided by the invention has the advantages of strong anti-attack ability and good safety of the image, and can be applied to copyright protection, restriction of illegally spreading audiovisual products, individual privacy protection, identification hiding and high-tech crime prevention.
Owner:XIDIAN UNIV
Fractional differential-based multi-feature combined sparse representation tracking method
InactiveCN106530329AImplement Adaptive UpdatesOvercoming the poor ability of single feature to describe the targetImage enhancementImage analysisFractional differentialFeature extraction
The invention provides a fractional differential-based multi-feature combined sparse representation tracking method. The method includes the following steps: in a frame of particle filtering, first, performing partitioning processing on a target image region, dividing the target region into 9 related and unequal subblocks according to the features of the target region, extracting the gray scale feature and HOG feature of each subblock, combining the two features to perform sparse representation on a target subblock, and also performing the same feature extraction and sparse representation on 8 adjacent regions around the target; then, adopting a nucleating accelerated neighbor gradient algorithm to jointly solve sparse coefficients of 9 candidate particles; and finally, regarding target blocks in different positions as different categories, utilizing a block of the same category as a candidate particle block and a representation coefficient in a dictionary to reconstruct the block, and building a likelihood function according to a reconstruction error to determine an optimal candidate particle, thereby realizing accurate tracking of a main target and 8 auxiliary targets.
Owner:NORTH CHINA ELECTRIC POWER UNIV (BAODING)
Forest region fire detection method and system based on infrared and visible video fusion
ActiveCN106897653ARich dataReal-time accurate automatic segmentationForest fire alarmsCharacter and pattern recognitionFractional differentialVideo image
The invention provides a forest region fire detection method based on infrared and visible video fusion, and the method comprises the steps: S1, respectively collecting and storing an infrared video image and a visible video image of a forest region; S2, carrying out the fusion of the infrared video image and the visible video image through an improved fractional differential method, and obtaining a fusion image; S3, calculating the fusion image, and determining a specific forest fire region. Meanwhile, the invention also proposes a forest region fire detection system, and the system comprises a data collection module which comprises an infrared collection submodule and a visible collection submodule, wherein the infrared collection submodule and the visible collection submodule are respectively used for collecting and storing the infrared video image and the visible video image of the forest region; an image fusion module which is used for carrying out the fusion of the infrared video image and the visible video image through the improved fractional differential method and obtaining the fusion image; and a fire detection module which carries out the calculation of the fusion image so as to obtain the specific forest fire region.
Owner:BEIJING FORESTRY UNIVERSITY +1
Corner detection method based on non-causal fractional gradient operator
ActiveCN106204570AHigh precisionAvoid weakeningImage enhancementImage analysisImaging processingFractional differential
The invention discloses a corner detection method based on a non-causal fractional gradient operator, which belongs to the technical field of image processing. According to the invention, non-causal fractional gradient operation of a gray-scale image to be detected is realized through the combination of cause-effect and anti-causal fractional integral and cause-effect and anti-causal fractional differential. The method comprises the steps that an image is read to generate a gray scale matrix f (x, y); non-causal fractional gradients Dx and Dy of f (x, y) in x and y directions are calculated; the product DxDy of the gradient direction is calculated; Gaussian kernel is used to filter DxDy; the corner point intensity is calculated; and non-maximum suppression is carried out to acquire an accurate image corner. According to the invention, the novel algorithm based on non-causal fractional gradient is used to carry out gradient and corner energy operation; the corner detection precision is improved; the method is suitable for the computer vision fields of image registration and matching, image fusion, target recognition and the like.
Owner:南京傲途软件有限公司
Fuzzy image super-resolution reconstruction method based on fractional differential
ActiveCN107424121AAvoid dependenceEnhanced Texture InformationGeometric image transformationFractional differentialReconstruction method
The invention provides a fuzzy image super-resolution reconstruction method based on fractional differential. The method comprises the steps of (1) carrying out Gauss fuzzy and down sampling processing on an original image set in order, and obtaining an input image sequence, (2) selecting one arbitrary frame of input image from the input image sequence to carry out bicubic interpolation amplification, and obtaining an original reference frame, (3) using an adaptive fractional differential algorithm to carrying out image enhancement processing on each frame of input image in the input image sequence and the original reference frame, (4) calculating a motion matrix between each frame of input image and the original reference frame through SIFT matching, and searching a point in each frame of input image corresponding to a point in the original reference frame, and (5) calculating a residual error between the point in the original reference frame and the corresponding point in each frame of input image, through residual error inverse iterative projection correction, and the pixel value of the point in the original reference frame is constantly adjusted until a preset condition is satisfied.
Owner:河南宝通信息安全测评有限公司
Fractional order cell neural network adaptive synchronization control and circuit design method
The invention discloses a fractional order cell neural network adaptive synchronization control and circuit design method. A fractional differential algorithm is selected, and the definition of a cell neural network equation is combined, thereby constructing a three-dimensional cell neural network system. The method comprises the steps: designing a drive-response system with a known drive system nonlinear parameter and an unknown response system nonlinear parameter based on the above system, constructing a new adaptive synchronizing controller and a parameter adaptive adjustment rate, and achieving the synchronization of the drive and response systems in numerical simulation; designing the circuit diagrams of the drive and response systems of the fractional order cell neural network, and achieving the circuit simulation of the controller and the adaptive adjustment rate. A simulation result indicates that the circuit simulation and the numerical simulation have the similar synchronous phase diagram, and the method verifies the accuracy of system theoretical analysis and the actual physical realizability. Therefore, the method is practical in the field of engineering.
Owner:JIANGXI UNIV OF SCI & TECH
Adhesion hemocyte image segmentation method based on improved fractional differential and graph theory
InactiveCN105809703AHigh precisionImage enhancementImage analysisPattern recognitionFractional differential
The invention relates to an adhesion hemocyte image segmentation method based on the improved fractional differential and graph theory.The method comprises the steps of pretreating a hemocyte image by combining morphological denoising with the improved quasi-circular mask operator fractional differential algorithm aiming at the phenomenon that the hemocyte image is fuzzy and low in contrast ratio, wherein by the adoption of the improved fractional differential algorithm, cell edge details are reserved while staining contamination and grain noise of the hemocyte image are filtered out; then conducting preliminary segmentation on the pretreated image with the watershed algorithm, and mapping an over-segmentation area into a node; finally conducting resegmentation on the cell image obtained in the second step with the improved graph theory minimum spanning tree (MST) algorithm.By the adoption of the method, segmentation precision of adherent cells in the cell image can be improved.
Owner:FUZHOU UNIV
Seismic horizon tracking preprocessing method based on fractional derivative
ActiveCN104062681AImprove computing efficiencyGood effectSeismic signal processingDiffusionPretreatment method
The invention provides a seismic horizon tracking preprocessing method based on a fractional derivative, which belongs to geophysical exploration field for petroleum and natural gas. The seismic horizon tracking preprocessing method comprises the following steps: (1) selecting a central pixel point of a seismic image, and then determining an order of a fractional differential; (2) selecting a filtering direction of an isotropy diffusion; (3) performing same-phase axis continuous enhancement on a central pixel point; (4) repeating the steps (1) to (3) on a next central pixel point until all pixel points are processed; (5) performing isotropy diffusion filtering processing; and (6) adjusting vertical resolution of the seismic image, and accordingly seismic horizon tracking preprocessing is finished. Through the method of the invention, transverse-direction continuity and vertical-direction resolution of a lineups can be controlled simultaneously. The preprocessing method for automatic tracking of seismic horizon has advantages of: simple process, high calculating efficiency and obvious effect.
Owner:CHINA PETROLEUM & CHEM CORP +1
Implantable pacemakers control and optimization via fractional calculus approaches
Method and system for non-linear modeling of physiological behavior, such as R-R intervals, in implantable devices, such as a rate responsive pacemakers, comprising a comprehensive modeling and optimization methodology based on fractional calculus and constrained finite horizon optimal control theory that allows for allows for fine-grain optimization of pacemaker response to heart rate variations; and the theoretical basis on which a hardware implementation of the fractional optimal controller that can respond to changes in the heart rate dynamics. Present invention describes a fractal approach to pacemaker control based on the constrained finite horizon optimal control problem. This is achieved by modeling the heart rate dynamics via fractional differential equations. Also, by using calculus of variations, the invention describes how the constrained finite horizon optimal control problem can be reduced to solving a linear system of equations. Finally, the invention describes the theoretical basis on which a hardware implementation become possible.
Owner:CARNEGIE MELLON UNIV
Fractional-order observability analysis method for pulsar navigation system
InactiveCN106092092AObservability analysis results are accurateSmall amount of calculationInstruments for comonautical navigationNavigation by astronomical meansNavigation systemObservability
The invention provides a fractional-order observability analysis method for a pulsar navigation system. The method comprises a preparation stage and a system observability analysis stage; the preparation stage comprises establishing a spacecraft orbit kinetic model and a pulsar navigation model which are demanded by navigation filtering; and the system observability analysis stage comprises working out the fractional differential of time by a measurement module, obtaining a measurement matrix of fractional order, constructing an observability analysis matrix, rearranging the condition number, calculating the condition number of exponential weighting, so as to obtain the observability analysis result. The observability analysis result obtained according to the technical scheme of the invention is relatively accurate, past measurement information is fully utilized, influence of orbit elements on navigation precision can be embodied, calculation is simple and the method is convenient to achieve, system resource is saved and analysis results can be efficiently obtained.
Owner:WUHAN UNIV OF SCI & TECH
Optimal-order image enhancement method based on fractional differential image enhancement algorithm
ActiveCN109636745AIncrease brightnessEnhance high-frequency detail informationImage enhancementFractional differentialDifferential algorithm
The invention discloses an optimal-order image enhancement method based on a fractional differential image enhancement algorithm, and the method comprises: calculating the gradient, information entropy, image brightness, human eye feeling brightness, and human eye contrast sensitivity functions of an image, so as to judge the characteristics of the image; performing normalization calculation on the gradient, the information entropy, the image brightness, the human eye feeling brightness and the human eye contrast sensitivity function of the image to obtain a value S; numerical values S representing image texture information, brightness and human eye visual perception are put into the logarithm compression curve to be compressed, and a corresponding optimal fractional order is obtained; Andusing the optimal fractional order in the fractional order differential algorithm of the image to realize self-adaptive image enhancement. Normalized local statistical information capable of representing image characteristics is constructed, a function relation between the orders and the normalized local statistical information is established, the normalized local information is used as an independent variable, a fractional order differential algorithm of the optimal order is obtained according to a logarithm function, and image enhancement is carried out.
Owner:SHAANXI SCI TECH UNIV
Target tracking method based on edge feature fusion
ActiveCN109410235AImprove robustnessImprove adaptabilityImage enhancementImage analysisImaging processingFractional differential
The invention belongs to the field of image processing and target tracking, in particular to a target tracking method fusing edge features. The R-L fractional differential edge detection operator andLaplacian edge detection operator are fused to construct a hybrid edge detection operator, which can detect the edge feature information of the target template and scene image. Based on the two histogram models of target chromaticity and edge feature, an adaptive fused backward probability projection map is established to improve the adaptability of the tracking method to uncertain environmental change information. The invention can be applied to a real-time monitoring system.
Owner:TIANJIN POLYTECHNIC UNIV
Novel WENO-format high-precision fractional derivative approximation method
PendingCN112307418ASimplify the solution processSolving Numerical Simulation ProblemsDesign optimisation/simulationCAD numerical modellingFractional differentialComputational physics
The invention discloses a novel WENO-format high-precision fractional derivative approximation method. The method comprises the steps: decomposing a Caputo fractional derivative in a fractional differential equation into a classical second derivative and a weak singular integral in a Cartesian coordinate system, discretizing the classical second derivative by using a novel WENO format, and solvingthe weak singular integral by using Gauss-Jacobi quadra-ture; for a time derivative in an equation, using a three-order TVD Runge-Kutta discrete formula to discretize a semi-discrete finite difference format into a space-time full-discrete finite difference format, wherein the space-time full-discrete finite difference format is an iterative formula about a time layer, and an initial state valueis known; and according to the space-time full-discrete finite difference format, solving an approximate value of a next time layer through an iterative formula, and sequentially acquiring a numericalsimulation value in a calculation region at the end moment. The method can achieve six-order precision in the smooth area of a solution, and can keep the property of basically no oscillation in a discontinuous strong interruption area.
Owner:NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
Fractional order edge detection method for noise pollution image
ActiveCN110163881AReduce distractionsTo achieve the effect of edge enhancementImage enhancementImage analysisPattern recognitionFractional differential
The invention discloses a fractional order edge detection method for a noise pollution image. The method is characterized by comprising the following steps: a noise pollution gray level image is denoised; the denoised image enters a two-dimensional fractional differential filter for edge extraction; the de-noising processing method comprises the following steps: carrying out convolution on a graylevel image and a fractional order integral filter or a Gaussian filter to obtain a filtered image; the edge extraction method comprises the following steps: carrying out convolution on a denoised image and two-dimensional fractional differential filter masks in the horizontal direction and the vertical direction, and solving a gradient image. The improved two-dimensional fractional order integralfilter and the improved two-dimensional fractional order differential filter are adopted, and when the improved two-dimensional fractional order integral filter and the improved two-dimensional fractional order differential filter are used for noise image edge detection at the same time, the characteristics of high robustness, edge positioning accuracy and edge enhancement on noise are achieved.
Owner:YUNNAN UNIV
NSCT domain infrared image enhancement method based on improved Retinex and quantum flora algorithm
InactiveCN110298807AIncrease contrastRich in detailsImage enhancementImage analysisFractional differentialDecomposition
The invention relates to an NSCT domain infrared image enhancement method based on improved Retinex and a quantum flora algorithm, and the method comprises the steps: carrying out the multi-scale andmulti-direction decomposition of an infrared image through employing NSCT transformation, and obtaining a low-frequency sub-band and a high-frequency sub-band; then, adopting an improved Retinex algorithm to enhance the low-frequency sub-band coefficient; introducing a quantum updating strategy of the nonlinear self-adaptive revolving door into a flora algorithm for optimizing fractional differential parameters, and performing denoising and enhancement on a high-frequency sub-band by combining a Bayes Shrink threshold value; and finally, performing NSCT inverse transformation on the processedlow-frequency sub-band coefficient and high-frequency sub-band coefficient to obtain an enhanced image. According to the method, the contrast, definition and information entropy of the infrared imageare greatly improved, the details of the infrared image are enhanced, and a more favorable infrared enhanced image is provided for subsequent infrared image processing.
Owner:FUZHOU UNIV
Medical image enhancement method combining fuzzy set and fractional differential
PendingCN110390652ASharp edge detailsImprove image qualityImage enhancementHaar waveletWavelet reconstruction
The invention provides a medical image enhancement method based on combination of a fuzzy set and fractional differential. The method comprises the following steps: decomposing an original medical image by using Haar wavelet transform to obtain a low-frequency sub-band component and a high-frequency sub-band component of the image; enhancing the extracted low-frequency sub-band components by adopting a fuzzy set method of an adaptive threshold to obtain enhanced low-frequency self-band components; constructing a mask by using fractional differential, and carrying out convolution operation on the mask and the high-frequency band component to obtain an enhanced high-frequency band component; and through wavelet reconstruction, performing combined reconstruction on the enhanced low-frequencyself-band component and the enhanced high-frequency band component, and recovering the enhanced image. Wavelet transform is utilized to decompose the image, different extracted frequency bands are enhanced by using different methods, the contrast of the enhanced image is higher, more texture details of the image are depicted, and edge contour details become clearer.
Owner:NORTHEASTERN UNIV
Multi-mode Lamb wave signal separation method based on fractional differential
PendingCN108921113AAchieve separationEfficient extractionCharacter and pattern recognitionComplex mathematical operationsFractional differentialPhase spectrum
The invention discloses a multi-mode Lamb wave signal separation method based on a fractional differential. The method comprises the following steps that: (1) calculating the Fourier transform of a multi-mode signal; (2) calculating the fractional differential of an amplitude spectrum; (3) calculating the multinomial coefficient of the fractional order and the fractional differential maximum valueof the amplitude spectrum of a Gaussian model; (4) calculating an amplitude spectrum parameter; (5) on the basis of the Gaussian model, calculating the amplitude spectrum; (6) calculating a phase spectrum; (7) extracting a single-mode Lamb wave signal by the amplitude spectrum and the phase spectrum; and (8) removing a mixed signal of which the signal is extracted, and repeating the above steps to realize the separation of each mode. Compared with the prior art, the method can extract the single-mode characteristic parameter of a multi-mode mixed signal through the fractional differential soas to more favorably keep the detail characteristic of each mode signal, each-mode characteristic parameter can be effectively extracted, and each-mode amplitude spectrum reconstruction is realized soas to realize the separation of the multi-mode mixing signals.
Owner:NANJING UNIV OF INFORMATION SCI & TECH
Fractional order differential filter for digital image
InactiveCN100536527CTelevision system detailsColor signal processing circuitsDigital videoSignal processing circuits
The digital image fractional differential filter proposed by the present invention is a signal processing circuit device for real-time enhancement of complex texture details of digital images. The fractional order differential filter of the digital image is composed of a digital video popular memory group, a phase lock / shift circuit group, a fractional order differential mask convolution circuit and a maximum value comparator in a cascaded manner. The operation rule of the first algorithm unit circuit to the eighth algorithm unit circuit in the fractional differential mask convolution circuit is to use the scheme of fractional differential mask convolution to realize spatial filtering of digital image fractional differential. The digital image fractional differential filter circuit proposed by the present invention has simple structure, concise operation rules, good texture detail enhancement effect, and high real-time performance, and is especially suitable for high-definition digital television, biomedical images, bank notes, and satellite remote sensing images. Applications such as real-time enhancement of complex texture details such as biometric images.
Owner:成都三足鸟科技有限公司
Time-frequency overlapping multi-mode lamb wave signal separation method
PendingCN109145726AReduce difficultyAchieve separationCharacter and pattern recognitionComplex mathematical operationsFractional differentialFrequency dispersion
The invention discloses a time-frequency overlapping multi-mode Lamb wave signal separation method, comprising the following steps: (1) frequency dispersion compensation of the multi-mode Lamb wave signal; (2) windowing the compensation signal; (3) Fourier transform of windowed signal; (4) calculating fractional derivative of amplitude spectrum; (5) calculating the fractional differential maximumof amplitude spectrum of Gaussian model and the polynomial coefficients of corresponding frequency and differential order; (6) calculating amplitude spectrum parameters; (7) calculating amplitude spectrum based on Gaussian model; (8) calculating and extracting non-dispersive Lamb wave signal by inverse Fourier transform; (9) recovery of Lamb wave signal by dispersion function; (10) the mixed signal after removing the extracted signal repeating the above steps to realize the separation of each pattern. Compared with the prior art, the invention can reduce the difficulty of the mixed signal through the frequency dispersion compensation, can effectively extract the characteristic parameters of each mode, and realize the reconstruction of the amplitude spectrum of each mode to realize the separation of the multi-mode mixed signal.
Owner:NANJING UNIV OF INFORMATION SCI & TECH
Motion Field Estimation Method for Movie MRI Image Sequences Based on Fractional Differentiation
InactiveCN103927725BOvercome the defect of losing image texture detailsUnaffected by changes in lightImage enhancementImage analysisFractional differentialNMR - Nuclear magnetic resonance
Owner:HARBIN INST OF TECH
Attitude stabilization control method of space-tethered grabber based on fractional order differentiation in stages
ActiveCN106647786BStable recyclingAvoid collisionAttitude controlSpace tetherFractional differential
The present invention relates to a fractional order differential-based staged space tethered capture device attitude stabilization control method. According to the method, the attitude stabilization controller of the recovery stage of a space tethered capture device is designed in a staged manner according to the features of a tether recovery stage, the design of the controller is more fuel-efficient and can avoid the collision of a space platform and a tail end capture device at the later period of the recovery stage; the fractional order differential controller is faster in input response and is small in overshoot compared with an integer-order controller; and when fractional order differential calculation is performed, a state at a previous time point is memorized, and therefore, with the controller provided by the invention adopted, a tether can be recovered more stably at the later period of the recovery stage with a recovery speed and a capture device attitude angle ensured.
Owner:NORTHWESTERN POLYTECHNICAL UNIV
Wavelet domain-based method for weighting fractional differential image digital watermark
InactiveCN102129655BOvercoming cracking problemsImprove securityImage data processing detailsImaging processingFractional differential
The invention provides a wavelet domain-based method for weighting a fractional differential image digital watermark, which mainly solves the problem that the high-frequency coefficient of an image undergoing wavelet decomposition is susceptible to extraneous noises and conventional image processing. The method comprises the implementation steps of: doing two different orders of differentials fora sinusoidal signal by utilizing a fractional order Cauchy formula; respectively carrying out discrete sampling and superposing by utilizing a given weight to generate a pseudorandom sequence and adding the pseudorandom sequence with a watermark pixel value to realize watermark scrambling; carrying out two-stage decomposition on a carrier image by utilizing a Haar wavelet and embedding the scrambled watermark information in the carrier image through the exchanged and decomposed high-frequency coefficient; and through comparing the high-frequency coefficient undergoing the two-stage decomposition by utilizing the Haar wavelet, extracting the scrambled watermark and subtracting the pseudorandom sequence to realize watermark recovery. The method provided by the invention has the advantages of strong anti-attack ability and good safety of the image, and can be applied to copyright protection, restriction of illegally spreading audiovisual products, individual privacy protection, identification hiding and high-tech crime prevention.
Owner:XIDIAN UNIV
Fractional Observability Analysis Method for Pulsar Navigation System
InactiveCN106092092BObservability analysis results are accurateSmall amount of calculationInstruments for comonautical navigationNavigation by astronomical meansNavigation systemObservability
The invention provides a fractional-order observability analysis method for a pulsar navigation system. The method comprises a preparation stage and a system observability analysis stage; the preparation stage comprises establishing a spacecraft orbit kinetic model and a pulsar navigation model which are demanded by navigation filtering; and the system observability analysis stage comprises working out the fractional differential of time by a measurement module, obtaining a measurement matrix of fractional order, constructing an observability analysis matrix, rearranging the condition number, calculating the condition number of exponential weighting, so as to obtain the observability analysis result. The observability analysis result obtained according to the technical scheme of the invention is relatively accurate, past measurement information is fully utilized, influence of orbit elements on navigation precision can be embodied, calculation is simple and the method is convenient to achieve, system resource is saved and analysis results can be efficiently obtained.
Owner:WUHAN UNIV OF SCI & TECH
An Image Filtering Method Based on Fractional Differential Estimation Gradient Domain
ActiveCN105160635BQuality improvementImplement image filteringImage enhancementFractional differentialSignal-to-noise ratio (imaging)
The invention discloses an image filtering method based on a fractional order differential estimation gradient domain. According to the method, in the value constraint Ed aspect, median values in a mask area are utilized to carry out value constraint; in the gradient constraint Eg aspect, gradient constraint based on integer order differential and edge constraint based on integer order differential are fused to obtain a gradient based on fractional order differential; when a direction histogram is calculated, Gauss weight of each direction area is employed to obtain a final gradient direction descriptor, and the direction histogram is constructed for direction constraint. The method takes the fractional order differential as a base, a relatively comprehensive and accurate filtering framework is obtained, so image filtering is better realized, and image filtering quality is improved. The method is applied to image light supplement, image de-noising and image sharpening, and a signal-to-noise ratio, the average gradient and the average information entropy of output images are higher than those of a traditional filtering framework.
Owner:江苏贝思旺科技有限公司
Method and system for constructing adaptive weight active contour model based on fractional differential information
The invention provides an adaptive weight activity contour model construction method based on the fractional order differential information and a system. The system comprises an input module, an initiation module, a first calculation module, a second calculation module, a determination module and an output module. The system is advantaged in that fractional order differential is introduced, a new difference image is constructed, a local term is constructed by utilizing the difference image, and a new activity contour model is proposed; by utilizing the fractional order gradient mode information, one adaptive weight is proposed, so local and global terms of the model can be dynamically adjusted; by utilizing change of an inner area of an evolution curve, a new evolution stop standard is proposed, and the evolution curve can automatically stop at a correct boundary.
Owner:SHENZHEN UNIV
A Preprocessing Method for Seismic Horizon Tracking Based on Fractional Derivatives
ActiveCN104062681BImprove computing efficiencyGood effectSeismic signal processingDiffusionFractional differential
The invention provides a seismic horizon tracking preprocessing method based on a fractional derivative, which belongs to geophysical exploration field for petroleum and natural gas. The seismic horizon tracking preprocessing method comprises the following steps: (1) selecting a central pixel point of a seismic image, and then determining an order of a fractional differential; (2) selecting a filtering direction of an isotropy diffusion; (3) performing same-phase axis continuous enhancement on a central pixel point; (4) repeating the steps (1) to (3) on a next central pixel point until all pixel points are processed; (5) performing isotropy diffusion filtering processing; and (6) adjusting vertical resolution of the seismic image, and accordingly seismic horizon tracking preprocessing is finished. Through the method of the invention, transverse-direction continuity and vertical-direction resolution of a lineups can be controlled simultaneously. The preprocessing method for automatic tracking of seismic horizon has advantages of: simple process, high calculating efficiency and obvious effect.
Owner:CHINA PETROLEUM & CHEM CORP +1
A Method of Image Fusion and Super-resolution Based on Variation and Fractional Differential
ActiveCN103854267BLower resolution requirementsQuality improvementImage enhancementTotal variation minimizationSource image
Owner:云南联合视觉科技有限公司
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