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1.
A system for superresolution of temporally restricted objects allows one to transmit ultrawideband optical signals (objects) through a narrow aperture. Such a system was proposed, improved, and implemented for one- and two-dimensional objects. Implementing frequency-plane enhancement in this system provides the ability of spatial filtering of ultrawideband objects. A method for spatial filtering in a system for superresolution of temporally restricted objects by use of a generalized Dammann grating is suggested. An experimental demonstration of high-frequency enhancement (high-pass filtering) of one-dimensional objects is presented.  相似文献   

2.
A method to synthesize a computer-generated hologram (CGH) of real-existing objects from projection images is proposed. Different from other similar methods, our method enables the synthesis of a CGH with only one-dimensional (1-D) mechanical scanning of the objects. Our method is connected with the three-dimensional (3-D) Fourier spectrum of the objects by the 3-D central slice theorem (CST). Two efficient recording techniques for projection images and numerical experiments to verify our principle is discussed. A comparison between the two techniques is also presented from the viewpoint of diffraction efficiency. © 2005 The Optical Society of Japan  相似文献   

3.
孔径旋转频闪散斑照相法测量物体的固有频率   总被引:2,自引:1,他引:1  
陈炳泉 《光学学报》2002,22(11):358-1361
提出了一种测量物体固有频率的新方法--孔径旋转频闪散斑照相法。该方法能方便地测量振动物体的固有频率,具有精度高、全场显示、条纹可见度好等优点,给出了理论分析和实验结果。  相似文献   

4.
张成  杨佐  祝雪莲  潘敏  韦穗 《光学学报》2020,(1):342-351
漫射物体的压缩全息利用其非相干散射密度函数在统计意义上满足稀疏先验这一假设,可以从多幅散斑图案实现漫射物体的层析重建,避免了散斑和不同平面的散焦图像之间的串扰。将单波长照明条件拓展到红、绿、蓝三色波长,提出一种新的适用于彩色漫射物体的压缩全息层析成像方法,搭建多波长照明条件下漫射物体的层析成像模型,并通过解压缩推理方法有效地分离不同平面的三维非相干密度函数。数值模拟实验表明,所提方法可以在多幅二维彩色散斑图案中成功进行彩色层析漫射物体的压缩重建,有效地抑制了散斑效应以及不同平面的散焦图像之间的相互串扰。  相似文献   

5.
1IntroduCtionThree-dimenShaalsensingis0fgreatimportanceinr0boicvision,aut0maticprocessing,b~dicineandcomPuter'animatdri-OPticalthree-dimensionalsenSngaregettingmoeandmoeimportantbecauseofitsadvantagesofnon-contact,highprecisionandaut0maticcontr0.TheoPticalthree-dimenAnalsensingmethodincludelasertriangulati0n['-'],Moreprofiboetry['1,FourierTransf0rmProfiIomtry(m)['J,andPhaseMeasurementProfilometry(PMP)[6].Exceptlasertriangulatdri,theabovemethOdsarefitforthree-dimensi0nalsensing0nlyfrOI…  相似文献   

6.
A generalized rule induction mechanism, immune algorithm, for knowledge bases is building an inheritance hierarchy of classes based on the content of their knowledge objects. This hierarchy facilitates group-related processing tasks such as answering set queries, discriminating between objects, finding similarities among objects, etc. Building this hierarchy is a difficult task for knowledge engineers. Conceptual induction may be used to automate or assist engineers in the creation of such a classification structure. This paper introduces a new conceptual rule induction method, which addresses the problem of clustering large amounts of structured objects. The conditions under which the method is applicable are discussed.  相似文献   

7.
Generalized Rule Induction Based on Immune Algorithm   总被引:1,自引:0,他引:1  
1 Introduction  Aruleinductionstructureisasetofhierarchicallyrelatedclasses,wherehierarchicallyhigherclassessubsumetheirlowercounter parts .Itcanbeviewedasanindex .Itsutilityisobviousfromtheefficiencypointofview .Buildingsuchastructureisadifficulttaskfor…  相似文献   

8.
A new method to remove the shadows in laser triangulation and a computer model for three-dimensional images with visual reality of three-dimensional diffuse objects are presented. The methods for acquiring color data in optical three-dimensional sensing are discussed. A method for obtaining three-dimensional images with visual reality of real objects is presented. The principles,the system structure and the experimental results are provided.  相似文献   

9.
 提出在迂回位相傅里叶变换计算全息图中利用合成谱记录多个物体的方法。该方法利用多个物体合成的傅里叶频谱,代替传统的迂回位相型计算全息图中的单一频谱,在一幅计算全息图中完成多个物体的编码。再现时多个物体同时再现在同一衍射级的周围,并且再现像的形式可以多种多样。采用液晶空间光调制器(LC SLM)完成计算全息图的光学再现,实验验证了方法的有效性。结果表明:该方法可有效提高计算全息图的信息容量。  相似文献   

10.
光电反馈式静电悬浮与静电悬浮力测定   总被引:1,自引:1,他引:0  
吴兰  黄峰 《光子学报》1999,28(8):690-695
本文提出光电反馈式静电悬浮的新方法,简要讨论静电悬浮的原理、装置及其光电反馈控制过程.采用铝片和CD光盘作为悬浮体,测定了不同静电电压和不同悬浮间距时的静电悬浮力,揭示了它们之间的相互关系.结果显示这两种悬浮体均可获得足够的静电悬浮力,证明了静电悬浮的可行性.静电悬浮方法的显着特点是既适用于导电体与非导电体的悬浮,又适用于磁性体与非磁性体的悬浮,克服了传统磁悬浮技术仅适用于磁性体的局限性,可广泛应用于精密元器件的悬浮与非接触无损操作.  相似文献   

11.
A method is described for studying the internal structure of noncrystalline objects which are weak x-ray absorbers. The method uses the conventional arrangement of plane-wave topography. The object to be investigated is immersed in a monochromatic pseudoplane wave formed by a highly asymmetric reflection off a perfect crystal or several crystals and introduces phase disruptions at the wave front. A perfect single crystal mounted behind the object in a Laue arrangement reveals these disturbances, forming a contrast image of the boundaries of the structural components of the object. The possibilities of the method are illustrated by photographs of objects of various natures. The features of the image contrasts are discussed and confirmed by experiments on test objects. Zh. Tekh. Fiz. 67, 68–77 (January 1997)  相似文献   

12.
A new efficient method for solving the problems of waves diffraction on complex-shaped objects with the use of their replacement by a group of bodies with more simple form (fragments of complex objects) is offered. By the expansion of the scattering patterns of separate bodies in the series of vector spherical harmonics, the problem is reduced to solving the algebraic system of equations. It is shown that the method possesses a high convergence rate. Examples of modeling the scattering patterns of various complex objects are considered. Reliability of the results obtained is validated using the Optical theorem.  相似文献   

13.
基于时空域的自动视频对象分割算法   总被引:1,自引:1,他引:0  
程淑红  胡春海 《应用光学》2009,30(5):768-771
提出一种在视频序列中从背景里分离出运动对象的方法.使用全局运动估计和补偿进行预处理后,对视频序列中相邻帧进行连续两次差分,利用自适应滤波滤除噪声,并进行形态学处理,差分交集技术消除覆盖、显露的背景及部分噪声,最后模板匹配和更新,不仅能够得到快速变化的对象,而且能够得到视频对象暂时停止运动的部分.实验结果表明,该方法能够自动从视频序列中较好地提取出运动对象,具有较强的鲁棒性.  相似文献   

14.
利用偏振技术识别人造目标   总被引:18,自引:1,他引:17  
孙玮  刘政凯  单列 《光学技术》2004,30(3):267-269
提出了一种利用目标的偏振信息识别人造目标的新型方法。利用自制的多波段偏振CCD地面实验装置获取目标的偏振图像,并提取其中的偏振信息。由于人造目标和自然目标的偏振特性上有较大差别,因而根据这些信息,通过较常规的图像处理手段,即可很好地识别出图像中的人造目标。实验证明,该方法识别自然背景下的人造目标是相当有效的。  相似文献   

15.
研究了用频域法实现圆环形目标物计数的方法。对空域中含有圆环形目标物的二值图像,经傅里叶变换后在频域内进行滤波,再经傅里叶反变换后取一阈值进行处理,则对应于圆环形目标物即变为一个实心体,然后对实心体进行计数即可实现对圆环形目标物的计数。对该方法进行了数学描述,并分别用模拟图像和实际图像进行了实验。结果表明,该方法消除噪声的效果好,对部分封闭圆的检测同样有效,且可用于目标物有粘连的情况。该方法对圆环形目标物的尺寸相差不大的情况更为有效。  相似文献   

16.
This paper presents an improved depth extraction method of 3D objects using computational integral imaging reconstruction (CIIR) based on the multiple windowing models. The proposed method records 3D objects using the lenslet array; and it reconstructs multiple sets of slice images from multiple CIIR methods based on the different windowing models. A depth map is then extracted by a block matching algorithm among multiple set of slice images. A preliminary experiment is carried out to show the feasibility of the proposed method. Experimental results indicate the proposed method outperforms the previous method with two windowing models.  相似文献   

17.
A simple method (speckle masking) for the reconstruction of real images from astronomical speckle photographs is described. This method is applicable to a restricted class of objects that includes double stars. Double stars are the object most frequently observed with speckle interferometry techniques. Certain other kinds of objects can also be investigated by the speckle masking method, which should work also at low light levels. Theory and laboratory experiments are presented.  相似文献   

18.
Inspection methods for space objects (SOs) using an active apparatus with onboard detecting equipment are considered. A method based on sequential maneuvering of a spacecraft inspector in the equatorial plane to the points of convergence with various inspected objects in crossed orbits is proposed.  相似文献   

19.
A method for reconstructing two-dimensional binary objects from its autocorrelation function is discussed. The objects consist of a finite set of identical elements. The reconstruction algorithm is based on the concept of class of element pairs, defined as the set of element pairs with the same separation vector. This concept allows solving the redundancy introduced by the element pairs of each class. It is also shown that different objects, consisting of equal number of elements and the same classes of pairs, provide Fraunhofer diffraction patterns with identical intensity distributions. However, the method predicts all the possible objects that produce the same Fraunhofer pattern.  相似文献   

20.
A method of reconstruction of the spatial phase distribution and the image of a scattering object from a recorded speckle pattern of the diffraction field has been developed and verified on test objects. The proposed method is based on an assumption that, for objects of a certain class, the phase difference between adjacent speckles in the far zone is equal to π. Digital records of Fourier speckle patterns and the corresponding digitally reconstructed images are presented.  相似文献   

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