CN106408532B - Synthetic aperture radar SAR image denoising method based on the estimation of shearing wave field parameter - Google Patents

Synthetic aperture radar SAR image denoising method based on the estimation of shearing wave field parameter Download PDF

Info

Publication number
CN106408532B
CN106408532B CN201610812151.6A CN201610812151A CN106408532B CN 106408532 B CN106408532 B CN 106408532B CN 201610812151 A CN201610812151 A CN 201610812151A CN 106408532 B CN106408532 B CN 106408532B
Authority
CN
China
Prior art keywords
coefficient
shearing wave
sar image
estimation
synthetic aperture
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201610812151.6A
Other languages
Chinese (zh)
Other versions
CN106408532A (en
Inventor
杨宁
路雅宁
郭雷
李晖晖
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Northwestern Polytechnical University
Original Assignee
Northwestern Polytechnical University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Northwestern Polytechnical University filed Critical Northwestern Polytechnical University
Priority to CN201610812151.6A priority Critical patent/CN106408532B/en
Publication of CN106408532A publication Critical patent/CN106408532A/en
Application granted granted Critical
Publication of CN106408532B publication Critical patent/CN106408532B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06TIMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T5/00Image enhancement or restoration
    • G06T5/70Denoising; Smoothing
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06TIMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T2207/00Indexing scheme for image analysis or image enhancement
    • G06T2207/10Image acquisition modality
    • G06T2207/10032Satellite or aerial image; Remote sensing
    • G06T2207/10044Radar image

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Theoretical Computer Science (AREA)
  • Radar Systems Or Details Thereof (AREA)

Abstract

The present invention relates to a kind of synthetic aperture radar SAR image denoising methods based on the estimation of shearing wave field parameter to be distributed the statistical property of description speckle noise with Rayleigh (Rayleigh) in the phase separation immunoassay processing of SAR image.Since the mathematic(al) representation of laplacian distribution model is simple, it is commonly available the analytic solutions of estimation in conjunction with bayesian theory, for representing the shearing wave coefficient of back scattering component, then indicates the probability density function of shearing wave coefficient using laplacian distribution.The experimental results showed that the denoising method based on shearing wave parameter Estimation has apparent inhibition to the coherent speckle noise in SAR image, and preferably maintain the Edge texture information in image.

Description

Synthetic aperture radar SAR image denoising method based on the estimation of shearing wave field parameter
Technical field
The SAR image denoising method that the invention belongs to be estimated based on shearing wave field parameter is related to a kind of based on shearing wave zone The synthetic aperture radar SAR image denoising method of parameter Estimation, can be applied to Single-Look SAR Image, removes the multiplying property of SAR image Coherent speckle noise.
Background technique
SAR (synthetic aperture radar (Synthetic Aperture Radar, abbreviation SAR)) is a kind of high-resolution imaging thunder It reaches, belongs to active remote sensing system, there are round-the-clock, round-the-clock, multipolarization, multi-angle of view, more angle of depression data retrieval capabilities and right The penetration performance of some atural objects is compared with other sensors, and more details can be presented, can be accurately determined the big of target area It is small, it can better discriminate between the characteristic of adjacent objects, however the coherent speckle noise that SAR image is intrinsic, seriously reduce SAR image Degree can be interpreted, the applications such as succeeding target detection, classification, identification and information extraction are affected.Therefore, to SAR image coherent spot The research of suppressing method just becomes a part particularly important in SAR image processing technique, and elementary object is to inhibit image Under the premise of homogeneous area speckle noise is horizontal, the detailed information such as image border and texture are kept.
Since SAR image speckle noise has the characteristics that multiplying property, relative to additive noise, spot inhibits more difficult.More rulers Spending geometrical analysis is " second of the small echo tide " risen in the world in recent years, overcomes small echo and is unable to rarefaction representation higher-dimension spy The shortcomings that sign, is increasingly taken seriously.The method for being absorbed in SAR image denoising is quite a few, such as SAR based on bent wave Curvelet Image de-noising method, denoising method based on Contourlet etc..However, in subsequent research, Qu Bo and profile Wave has been demonstrated do not have translation invariance, so the application in image de-noising method is restricted.Shear wave conversion due to Its stability, directional sensitivity, translation invariance and optimal sparse approximation, the advantages that being easily achieved, are in numerous more rulers Show one's talent in degree geometrical analysis tool, huge potentiality are shown in terms of the edge extracting of image and denoising.But at present Gaussian noise removal is similar to based on shearing the algorithm of wave zone SAR image denoising, using coherent speckle noise after logarithm process Transformation coefficient is either divided into the method that texture, edge and smooth area three classes are handled by method processing, is not accounted for mostly The model of noise.
Summary of the invention
Technical problems to be solved
In order to avoid the shortcomings of the prior art, the present invention proposes a kind of synthesis hole based on the estimation of shearing wave field parameter Diameter radar SAR image denoising method.
Technical solution
A kind of synthetic aperture radar SAR image denoising method based on the estimation of shearing wave field parameter, it is characterised in that step It is as follows:
Step 1, shearing wave Shearlet are decomposed: being done shearing Wave Decomposition to the SAR image of the speckle noise Han multiplying property, divided Coefficient S after solution, indicates low-frequency approximation coefficient with L (S), indicates high frequency detail coefficient with Y (S);
Step 2, parameter Estimation:
Utilize the attenuation parameter α of low-frequency approximation coefficient L (S) estimation noise variance σ and rayleigh distributed:
The edge standard deviation sigma of each coefficient is estimated using high frequency detail coefficient Y (S)s(s), local auto-adaptive threshold value λ is calculated Soft-threshold processing is done with to current coefficient;
The edge standard deviation sigma of each coefficients(s):
Wherein: N (s) is the neighborhood window centered on current coefficient y (s), and M is coefficient number in window;
Calculate local auto-adaptive threshold value λ:
Soft-threshold processing is done to current coefficient:
Wherein: sign (y) is sign function,
()+It is indicative function,
Step 3, shearing wave inverse transformation reconstruct: to treated, low-frequency approximation coefficient L (S) and high frequency detail coefficient Y (S) is done Shearing wave inverse transformation, the recovery image after being denoised.
The step 1 carries out shearing wave conversion to the SAR image comprising multiplying property speckle noise, Decomposition order 4, in window Coefficient number is 3 × 3.
Beneficial effect
A kind of synthetic aperture radar SAR image denoising method based on the estimation of shearing wave field parameter proposed by the present invention, In the phase separation immunoassay processing of SAR image, the statistical property of description speckle noise is distributed with Rayleigh (Rayleigh).It is general due to drawing The mathematic(al) representation of Lars distributed model is simple, and the analytic solutions of estimation are commonly available in conjunction with bayesian theory, after representing To the shearing wave coefficient of scattering component, then the probability density function of shearing wave coefficient is indicated using laplacian distribution.
Shearing wave conversion is a kind of multi-scale geometric analysis (Multiscale Geometric more suitable for image procossing Analysis, MGA) method, have many advantages, such as stability, directionality, translation invariance and be easily achieved, wherein translation Invariance makes it more suitable for image denoising.Synthetic aperture radar (SAR) image has very strong coherent speckle noise, how to keep It is all that the difficult point that SAR image is handled is asked that preferable Speckle reduction effect is obtained on the basis of edge and grain details all the time One of topic.Based on shearing wave to the optimum linearity approximation capability of high dimensional data, shearing wave conversion is introduced into SAR image denoising, it is right The target signature for shearing the coefficient combination SAR image of wave conversion is handled.Laplce's mould is used to the signal in SAR image Type, the rayleigh model that multiplicative noise is used to coherent speckle noise use class to transformation coefficient using Bayes's method for parameter estimation New shearing wave transformation coefficient is obtained after being similar to the method processing of soft-threshold.Despeckle image is obtained after reconstruct.The experimental results showed that Denoising method based on shearing wave parameter Estimation has apparent inhibition to the coherent speckle noise in SAR image, and preferably keeps Edge texture information in image.
Detailed description of the invention
Fig. 1: the basic flow chart of the method for the present invention
Fig. 2: true SAR image denoising result:
(a) SAR image, (b) mean filter, (c) median filtering, (d) LEE is filtered, (e) Wiener filtering, and (f) small echo is filtered Wave, (g) bent wave filtering, (h) denoising result of this method
Specific embodiment
Now in conjunction with embodiment, attached drawing, the invention will be further described:
Hardware environment for implementation is: Intel (R) core (TM) i5-3230M computer, 4GB memory, operation it is soft Part environment is: Matlab7.0 and Windows 8.Method proposed by the present invention is realized with Matlab programming language.Image Data simulate SAR image and a width true picture SAR image using the method for multiplicative noise is added on natural image.
Present invention specific implementation is as follows:
Step 1: shearing wave (Shearlet) decomposes: doing shearing Wave Decomposition to the SAR image of the speckle noise Han multiplying property, obtains Coefficient S after decomposition, indicates low-frequency approximation coefficient with L (S), indicates high frequency detail coefficient with Y (S);
Step 2: parameter Estimation
1) the attenuation parameter α of low-frequency approximation coefficient L (S) estimation noise variance σ and rayleigh distributed is utilized;
2) high frequency detail coefficient processing: to high frequency detail coefficient Y (S):
A) estimate the edge standard deviation sigma of each coefficients(s):
Wherein N (s) is the neighborhood window centered on current coefficient y (s), and M is coefficient number in window.
B) local auto-adaptive threshold value λ is calculated:
C) soft-threshold processing is done to current coefficient:
Sign (y) is sign function,
()+It is indicative function,
Step 3: shearing wave inverse transformation reconstruct: to treated, low-frequency approximation coefficient L (S) and high frequency detail coefficient Y (S) is done Shearing wave inverse transformation, the recovery image after being denoised.
For simulating SAR image obtained by natural image addition multiplicative noise, by the resulting denoising result of the present invention and other The resulting result of denoising method compares, and it is as shown in table 1 to objectively evaluate result difference.
The different indexs that objectively evaluate have different physical significances, using mean value, equivalent number, edge conservation degree, letter Make an uproar than and Y-PSNR evaluate the effect of speckle noise filtering algorithm.
Edge conservation degree β (edge preservation measure) is defined as:
Wherein Δ S,Be S andPass through the high-pass filtering result of 3 × 3 standard Laplace operators.For ideal side Edge is kept, and β should be close to 1.
The common counter for evaluating SAR image coherent speckle noise intensity is equivalent number, from table 1 (lena simulates SAR image) Various denoising evaluation indexes in as can be seen that the Speckle reduction effect of mean filter and median filtering is obviously poor, denoising Still considerable speckle noise is remained in figure, equivalent number numerical value is smaller, and the effect of LEE filtering is slightly good, but denoises figure As excessively smooth;Wavelet filtering obviously obscures denoising result figure, and the denoising method based on warp wavelet inhibits big portion The speckle noise divided, but since warp wavelet is non-translation invariant, so occurring apparent scratch in denoising result figure. In contrast, this method is preferable on improvement of visual effect based on the denoising method of parameter Estimation.From the denoising result of true SAR image It is basic it can be concluded that conclusion identical with simulation SAR denoising result from the point of view of figure, and although equivalent view that bent wave filtering method obtains Number numerical value highest, but there is apparent scratch in filter result image, and in contrast, this method is relatively positive due to parameter Estimation Really, the edge conservation degree and signal-to-noise ratio numerical value obtained is optimal.
The true SAR image of table 1 denoises Contrast on effect

Claims (2)

1. a kind of synthetic aperture radar SAR image denoising method based on the estimation of shearing wave field parameter, it is characterised in that step is such as Under:
Step 1, shearing wave Shearlet are decomposed: shearing Wave Decomposition are done to the SAR image of the speckle noise Han multiplying property, after obtaining decomposition Coefficient S, low-frequency approximation coefficient is indicated with L (S), high frequency detail coefficient is indicated with Y (S);
Step 2, parameter Estimation:
Utilize the attenuation parameter α of low-frequency approximation coefficient L (S) estimation noise variance σ and rayleigh distributed:
σ=Median | L (S) | }/0.6745
The edge standard deviation sigma of each coefficient S is estimated using high frequency detail coefficient Y (S)s(S), local auto-adaptive threshold value λ and right is calculated Current coefficient does soft-threshold processing;
The edge standard deviation sigma of each coefficients(S):
Wherein: N (S) is the neighborhood window centered on current coefficient y (S), and M is coefficient number in window;
Calculate local auto-adaptive threshold value λ:
Soft-threshold processing is done to current coefficient:
Wherein: sign (y) is sign function,
()+It is indicative function,
Step 3, shearing wave inverse transformation reconstruct: to treated, low-frequency approximation coefficient L (S) and high frequency detail coefficient Y (S) is sheared Wave inverse transformation, the recovery image after being denoised.
2. the synthetic aperture radar SAR image denoising method according to claim 1 based on the estimation of shearing wave field parameter, special Sign is: the step 1 carries out shearing wave conversion to the SAR image comprising multiplying property speckle noise, Decomposition order 4, in window Coefficient number is 3 × 3.
CN201610812151.6A 2016-09-09 2016-09-09 Synthetic aperture radar SAR image denoising method based on the estimation of shearing wave field parameter Active CN106408532B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201610812151.6A CN106408532B (en) 2016-09-09 2016-09-09 Synthetic aperture radar SAR image denoising method based on the estimation of shearing wave field parameter

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201610812151.6A CN106408532B (en) 2016-09-09 2016-09-09 Synthetic aperture radar SAR image denoising method based on the estimation of shearing wave field parameter

Publications (2)

Publication Number Publication Date
CN106408532A CN106408532A (en) 2017-02-15
CN106408532B true CN106408532B (en) 2018-12-11

Family

ID=57999014

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201610812151.6A Active CN106408532B (en) 2016-09-09 2016-09-09 Synthetic aperture radar SAR image denoising method based on the estimation of shearing wave field parameter

Country Status (1)

Country Link
CN (1) CN106408532B (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111242856B (en) * 2020-01-06 2023-03-24 西安工程大学 Dual image denoising method based on shear wave
CN112098997B (en) * 2020-09-18 2021-10-15 欧必翼太赫兹科技(北京)有限公司 Three-dimensional holographic imaging security inspection radar image foreign matter detection method
CN112927165A (en) * 2021-03-22 2021-06-08 重庆邮电大学 SAR image speckle suppression method based on NSST domain three-dimensional block matching

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2146315A1 (en) * 2008-07-16 2010-01-20 Galileian Plus s.r.l. Method of filtering SAR images from speckle noise and related device.
CN102663679A (en) * 2012-03-02 2012-09-12 西北工业大学 Image denoising method based on Shearlet contraction and improved TV model

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2146315A1 (en) * 2008-07-16 2010-01-20 Galileian Plus s.r.l. Method of filtering SAR images from speckle noise and related device.
CN102663679A (en) * 2012-03-02 2012-09-12 西北工业大学 Image denoising method based on Shearlet contraction and improved TV model

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
An Improved Image Denoising Algorithm based on Shearlet;Zhiyong Fan et al;《International Journal of Signal Processing.Image Processing and Pattern Recognition》;20130831;第6卷(第4期);第475-483页 *
基于贝叶斯估计的剪切波域局部自适应图像去噪;龚俊亮 等;《液晶与显示》;20131031;第28卷(第5期);第799-804页 *

Also Published As

Publication number Publication date
CN106408532A (en) 2017-02-15

Similar Documents

Publication Publication Date Title
CN102324021B (en) Infrared dim-small target detection method based on shear wave conversion
CN103279957B (en) A kind of remote sensing images area-of-interest exacting method based on multi-scale feature fusion
CN103093441B (en) Based on the non-local mean of transform domain and the image de-noising method of two-varaible model
CN109919870B (en) SAR image speckle suppression method based on BM3D
CN103295204B (en) A kind of image self-adapting enhancement method based on non-down sampling contourlet transform
Hou et al. SAR image ship detection based on visual attention model
CN101482969B (en) SAR image speckle filtering method based on identical particle computation
CN106408532B (en) Synthetic aperture radar SAR image denoising method based on the estimation of shearing wave field parameter
CN102999908A (en) Synthetic aperture radar (SAR) airport segmentation method based on improved visual attention model
Liu et al. Image denoising based on improved bidimensional empirical mode decomposition thresholding technology
CN102609903A (en) Method for segmenting moveable outline model image based on edge flow
CN108428221A (en) A kind of neighborhood bivariate shrinkage function denoising method based on shearlet transformation
CN103077507A (en) Beta algorithm-based multiscale SAR (Synthetic Aperture Radar) image denoising method
CN102521811A (en) Method for reducing speckles of SAR (synthetic aperture radar) images based on anisotropic diffusion and mutual information homogeneity measuring degrees
CN103426145A (en) Synthetic aperture sonar speckle noise suppression method based on multiresolution analysis
CN102289800B (en) Contourlet domain image denoising method based on Treelet
Sulochana et al. Denoising and dimensionality reduction of hyperspectral images using framelet transform with different shrinkage functions
Scharfenberger et al. Image saliency detection via multi-scale statistical non-redundancy modeling
CN103345739B (en) A kind of high-resolution remote sensing image building area index calculation method based on texture
Hazarika et al. Sar image despeckling based on combination of laplace mixture distribution with local parameters and multiscale edge detection in lapped transform domain
Zhang et al. An improved edge detection algorithm based on mathematical morphology and directional wavelet transform
Zhang et al. Bayesian-based speckle suppression for SAR image using contourlet transform
Li et al. Algorithm of Canny Operator Edge Pre-processing Based on Mathematical Morphology
Guo et al. An Image Denoising Algorithm based on Kuwahara Filter
Huo et al. Seafloor segmentation using combined texture features of sidescan sonar images

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant