基于小波变换和直方图均衡的红外图像增强
基于红外图像低分辨率、低对比度、视觉特性差的特性，以及传统的利用直方图均衡化进行红外图像增强的方法会丢失图像的细节信息、增强红外图像的噪声的特性，将小波变换的多尺度、多分辨率的特点和直方图均衡化的方法相结合，提出一种更好的实现红外图像增强的算法。激光与红外No.22013尹士畅等基于小波变换和直方图均衡的红外图像增强227度下的原因,手臂的温度和环温比较接近,从而使得得到的图像的对比度比较差,视觉效果不明显。如图2中为经过小波变换后提取出来的图像的低频成分,从中可以看出,该图像和原始图像的对比度差别不大,但是从视觉上来看,图片的连续性较好,噪声较少。图3是经过直方图均衡化处理的图像,经过直方图均衡化之后图像的整体的视觉效果变好了,图片中手表和手臂的对比度非常明显,甚至包括表图4本文增强算法带和手臂的也可以清楚地辨认出来。然而,经过直7结论方图均衡化之后,手臂左下角方向和右下角方向以针对直方图均衡化和小波变换在红外图像增强及手表中央的噪声也变得非常的大,相比较原始图存在的问题,本文所提出的改进算法,通过将两者的像而言信噪比变差了。图4则是将直方图均衡化和优势相结合,弥补单独算法的劣势,从而达到适当提小波变换算法相结合后增强的红外图像,相比较图高原始红外图像的对比度,增强了目标和背景的差3而言,对比度的变化不大,但是图像的很多噪声特异性并且保证红外图像的信噪比的效果。性得到了改善,尤其是手表中央和手臂的左右下角部分的噪声得到了明显改善,从而很好的验证了该参考文献:算法的可行性。[1 Lin Zhenxian Song Guoxiang, Xue Wen Comparison andimprovements of several methods wavelet image denoising[ J]. Journal of Xidian University, 2004, 31(4)625-629.( in Chinese)林椹尠,宋国乡,薛文.图像的几种小波去噪方法的比较和改进[J].西安电子科技大学学报,2004,31(4):625-6292 Yu Tianhe, Hao Fuchun, Kang Weimin Summarization onthe infrared image enhancement technology [J]. Infrared图1原始红外图像and Laser Engineering, 2007, S2): 131-137.( in Chinese于天河,郝富春,康为民红外图像增强技术综述[J]红外与激光工程,2007,(S2):131-137[3 Xie Jiecheng, Zhang Dali, Xu Wenli. Wavelet Image De-noising vigorously [ J]. Journal of Image and Graphics2002,7(3):209-218.( in Chinese)谢杰成,张大力,徐文立小波图象去噪综述[J].中国图象图形学报,2002,7(3):209-218图2低频红外图像[4 Peng Zhou, Zhao Baojun. Nover scheme for infrared imageenhancement based on contourlet transform and fuzzy theory[J]. Laser& nfrared,2011,41(6):129-133.彭洲,赵保军.基于 Contourlet变换和模糊理论的红外图像增强算法[J].激光与红外,2011,41(6):129-133[5 Yong Yang, Wang Jingru, Zhang Qiheng. Enhancement oflow Contrast Image Contain Small Targ[ J]. Laser &Infrared,2005,35(5):373-377.( in Chinese)图3直方图均衡化雍杨,王敬儒,张启衡.弱小目标低对比度图像增强算228激光与红外第43卷法研究[J].激光与红外,205,35(5):373-377round[ J. Laser Infrared, 2003, 33(6): 109-114.[6 An Chengbin, Ren Hongliang, Nei Chuanhong, et al. Infraincsered Image Enhancement Technology for Staring Infrared温佩芝,史泽林,于海斌基于小波变换的复杂海面背Imager[ J]. Laser Infrared, 2003, 33(6): 32-33. (in景红外小目标检测[J]激光与红外,2003,33(6)nese109-114安成斌任宏亮,传虹,等凝视焦平面热像仪的红[11]孙延奎小波分析及其应用M].北京:机械工业出版外图像增强技术[J].激光与红外,203,33(6):社,2005[12] Turghunjan, et al. a technique of image enhancement[7]宋芳莉图像边缘检测中的方法研究[D].西安:西北based on the dyadic wavelet transform[ J]. Joumal of Xin-大学,2002jiang Normal University Natural Science Edition, 2006[8 Luo Jiebo, Chen Changwen, Parker K J Image enhancement25(4):6-13for low bit rate wavelet-based compression[ J]. IEEE Inter吐尔洪江,等.基于二进小波变换的图像增强技术national Symposium on Circuits and Systems, 1997: 6-20[J].新疆师范大学学报:自然科学版,2006,25(4)[9 Ji Shupeng, Ding Xiaoqing. Study on image enhancing fusion algorithm of visible and infrared image[J]. Laser [13]S Mallat. a Wavelet Tour of Signal Processing[ M].PittsInfrared, 2002, 31(6): 518-521.( in Chinese): Academic Press, 1999.吉书鹏,丁晓青.可见光与红外图像增强融合算法矸4]张德丰 MATLAB小波分析[M].机械工业出版社究[J激光与红外,2002,31(6):518-5212009[10] Wen peizhi, Shi Zhelin, Yu haibin. Wavelet transform-[15]葛哲学,沙威.小波分析理论与 MATLAB R007实现based Detection for Small IR Target in Complex Sea Back-[M].北京:电子工业出版社,2007
- 2020-12-03下载
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平面变压器3D仿真资料
采用COMSOL软件，对平面变压器的仿真过程进行叙述，让大家了解平面变压器的仿真流程，是个很好的指导教材Solved with COMSOL Multiphysics 5.0Results and discussionThe magnetostatic analysis yields an inductance of 0. 1l mH and a dc resistance of0. 29 mQ2. Figure 2 shows the magnetic flux density norm and the electric potentialdistributionvolume: Coil potentiaL()Volume: Magnetic flux density norm (t▲0.07▲2.88×10-42.51.50.03050.01V656×107v0igure 2: Magnetic flux density norm and electric potential distribution for themagnetostatic analysisIn the static (DC) limit, the potential drop along the winding is purely resistive andcould in principle be computed separately and before the magnetic flux density iscomputed. When increasing the frequency, inductive effects start to limit the currentand skin effect makes it increasingly difficult to resolve the current distribution in thewinding. At sufficiently high frequency, the current is mainly flowing in a thin layernear the conductor surface. When increasing the frequency further. capacitive effectscome into play and current is flowing across the winding as displacement currentdensity. When going through the resonance frequency, the device goes from behavingas an inductor to become predominantly capacitive. At the self resonance, the resistivelosses peak due to the large internal currents Figure 4 shows the surface current3 MODELING OF A 3D INDUCTORSolved with COMSOL Multiphysics 5.0distribution atl MHz. Typical for high frequency the currents are displaced towardsthe edges of the conductor.freq(1)=1.0000E6_Surfaee: Surface-current density norm (A/)▲18618Q16010￥1.02Figure 3: Surface current density at I MHz (below the resonance frequency)Figure 4 shows how the resistive part of the coil impedance peaks at the resonancefrequency near 6MHz whereas Figure 5 shows how the reactive part of the coiimpedance changes sign and goes from inductive to capacitive when passing throughthe resonance4 MODELING OFA3DINDUCTORSolved with COMSOL Multiphysics 5.0Global: Lumped port impedance(Q2)d port impedance7.5G6.583275655545352510.10.20.30.40.509igure 4: Real part of the electric potential distribution5 MODELING OF A INDUCTORSolved with COMSOL Multiphysics 5.0Global: Lumped port impedance(Q2)35000Lumped port impedance200001000050000500010000-1500020000250000.10.20.30.40.50.60.70.809Figure 5: The reactive part of the coil impedance changes sign hen passing through theresonance frequency, going from inductive to capacitiveModel library path: ACDC_Module/Inductive_ Devices_and_coils/inductor 3dFrom the file menu. choose newNEWI In the new window click model wizardMODEL WIZARDI In the model wizard window click 3D2 In the Select physics tree, select AC/DC> Magnetic Fields(mf)3 Click Add4 Click StudyMODELING OF A3D NDUCTORSolved with COMSOL Multiphysics 5.05 In the Select study tree, select Preset Studies>StationaryGEOMETRYThe main geometry is imported from file. Air domains are typically not part of a CaDgeometry so they usually have to be added later. For convenience three additionaldomains have been defined in the CAd file. These are used to define a narrow feed gapwhere an excitation can be appliedport l(impl)I On the model toolbar, click Import2 In the Settings window for Import, locate the Import section3 Click Browse4 Browse to the models model library folder and double-click the filenductor 3d. mphbinSphere /(sphl)I On the Geometry toolbar, click Sphere2 In the Settings window for Sphere, locate the Size section3 In the Radius text field, type 0.2ick to expand the Layers section. In the table, enter the following settingsLayer nameThickness(m)ayer0.055 Click the Build All Objects buttonForm Union(fin)i On the Geometry toolbar, click Build AllClick the Zoom Extents button on the Graphics toolbar7 MODELING OF A 3D INDUCTORSolved with COMSOL Multiphysics 5.03 Click the Wireframe Rendering button on the Graphics toolbarThe geometry should now look as in the figure below0.1-0.10.20.0.0.1y0.0.2Next, define selections to be used when setting up materials and physics Start bdefining the domain group for the inductor winding and continue by adding otheruseful selectionsDEFINITIONSExplicitI On the Definitions toolbar, click Explicit2 In the Settings window for Explicit, in the Label text field, type Winding3 Select Domains 7,8 and 14 onlyI On the Definitions toolbar, click Explicit2 In the Settings window for Explicit, in the Label text field, type Gap3 Select domain 9 onlI On the Definitions toolbar, click Explicit8 MODELING OF A3DINDUCTORSolved with COMSOL Multiphysics 5.02 In the Settings window for Explicit, in the Label text field, type core3 Select Domain 6 onlyExplicit 4I On the Definitions toolbar, click Explicit2 In the Settings window for Explicit, in the Label text field, type InfiniteElements3 Select Domains 1-4 and 10-13 onlyExplicit 5I On the Definitions toolbar, click Explicit2 In the Settings window for Explicit, in the Label text field, type Non-conducting3 Select Domains 1-6 and 9-13 onlyI On the Definitions toolbar, click Explicit2 In the Settings window for Explicit, in the Label text field, type Non-conductingwithout Ie3 Select Domains 5, 6, and 9 only.Infinite Element Domain /(iel)Use infinite elements to emulate an infinite open space surrounding the inductorI On the definitions toolbar click Infinite element domain2 In the Settings window for Infinite Element Domain, locate the Domain Selectionsection3 From the Selection list. choose Infinite Elements4 Locate the Geometry section From the Type list, choose SphericalNext define the material settingsADD MATERIALI On the Model toolbar, click Add Material to open the add Material window2 Go to the Add material window3 In the tree, select AC/DC>Copper.4 Click Add to Component in the window toolbar9 MODELING OF A 3D INDUCTORSolved with COMSOL Multiphysics 5.0MATERIALSCopper(mat/)I In the Model Builder window, under Component I(comp l)>Materials click Copper(matD)2 In the Settings window for Material, locate the Geometric Entity Selection section3 From the Selection list, choose windingADD MATERIALI Go to the Add Material window2 In the tree. select built-In>Air3 Click Add to Component in the window toolbarMATERIALSAir(mat2I In the Model Builder window, under Component I(comp l)>Materials click Air(mat2)2 In the Settings window for Material, locate the Geometric Entity Selection section3 From the Selection list, choose Non-conductingThe core material is not part of the material library so it is entered as a user-definedmateriaMaterial 3(mat3)I In the Model Builder window, right-click Materials and choose Blank Material2 In the Settings window for Material, in the Label text field, type Core3 Locate the geometric Entity Selection section4 From the selection list choose Core5 Locate the Material Contents section. In the table, enter the following settingsPropertName Value Unit Property groupElectrical conductivity sigma0S/IBasicRelative permittivity epsilonrBasicRelative permeability mur1e3Basic6 On the model toolbar. click Add Material to close the Add Material windowMAGNETIC FIELDS (MF)Select Domains 1-8 and 10-14 only0MODELING OF A 3D INDUCTOR
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