Topical Meeting on Signal Recovery and Synthesis with Incomplete Information and Partial Constraints最新文献_第3页

Bayesian Approach to Limited-Angle CT Reconstruction* 有限角度CT重建的贝叶斯方法*

Topical Meeting on Signal Recovery and Synthesis with Incomplete Information and Partial Constraints Pub Date : 1900-01-01 DOI: 10.1364/srs.1983.fa6

K. Hanson, G. W. Wecksung

{"title":"Bayesian Approach to Limited-Angle CT Reconstruction*","authors":"K. Hanson, G. W. Wecksung","doi":"10.1364/srs.1983.fa6","DOIUrl":"https://doi.org/10.1364/srs.1983.fa6","url":null,"abstract":"Consider the function f(x,y) to belong to the set of all integrable functions with compact support. The projections of f(x,y) may generally be written as where the hi are strip-like response functions corresponding to each of the N available projection measurements. The objective of computed tomography (CT) is to reconstruct the source function f(x,y) from these N measurements. Clearly a limited number of such measurements cannot completely specify an arbitrary f(x,y). Since Eq. 1 may be viewed as an inner product between hi and f in the Hilbert space of all acceptable functions, each measurement consists of a projection of the unknown vector f onto the basis vector hi. The available measurements can only provide Information about those components off that lie in the subspace spanned by the response functions called the measurement subspace. The components off that lie in the orthogonal (null) subspace do not contribute to the measurements and, hence, cannot be determined from the measurements alone. Without prior information about f(x,y) it is at least necessary to restrict the solution to the measurement space in order to make it unique, i.e., have minimum norm. The null-space components of such a solution are obviously zero. It is known that this leads to identifiable, objectionable artifacts when the projections span a limited range of angles.1,2 In its generality, Eq. 1 is representative of any discretely sampled, linear-imaging process. Thus, the above statements and the approach that follows are applicable to many other problems such as restoration of blurred images and coded-aperture imaging.","PeriodicalId":279385,"journal":{"name":"Topical Meeting on Signal Recovery and Synthesis with Incomplete Information and Partial Constraints","volume":"175 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120866611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Phase Synchronization of Distorted Imaging Antenna Arrays 畸变成像天线阵列的相位同步

Topical Meeting on Signal Recovery and Synthesis with Incomplete Information and Partial Constraints Pub Date : 1900-01-01 DOI: 10.1364/srs.1983.fa15

B. Steinberg

引用次数: 0

Electromagnetic image reconstruction techniques in inhomogeneous media satisfying the Born-Rytov approximation 满足Born-Rytov近似的非均匀介质中的电磁图像重建技术

Topical Meeting on Signal Recovery and Synthesis with Incomplete Information and Partial Constraints Pub Date : 1900-01-01 DOI: 10.1364/srs.1983.wa22

W. Boerner

{"title":"Electromagnetic image reconstruction techniques in inhomogeneous media satisfying the Born-Rytov approximation","authors":"W. Boerner","doi":"10.1364/srs.1983.wa22","DOIUrl":"https://doi.org/10.1364/srs.1983.wa22","url":null,"abstract":"The basis for developing projection tomographic reconstruction algorithms has been the assumption of straight-line ray-path propagation. But, in the case in which propagation occurs within discretely inhomogeneous media at wavelengths of the order of the size of the scatterer, phenomena such as refraction, reflection and diffraction can no longer be neglected and a straight-line projection tomographic approach fails. This is especially evident when a large difference in refractive index occurs, such as that encountered with dm-to-mm-wave propagation in inhomogeneous atmospheric media, representing hydrometeorite distributions, the marine ocean boundary layer, the ground surface underburden, or bone and soft layers within soft tissue. An exact solution for the general vector scattering case which strictly requires a polarimetric radiative transfer approach is not available, and in this research, the assumption is made that the media are weakly diffracting so that the Born and Rytov approximations are valid. Based on this assumption, various diffraction imaging methods were developed most recently, and we are basing our studies on Devaney's back-propagation tomographic approach which was developed upon the scalar wave theory. It is the main objective of this research to extend this work to the realm of electromagnetic vector wave theory for the improved diffraction-corrected imaging of radar targets embedded in clutter within the dm-to-mm-wavelength region of the electromagnetic spectrum.","PeriodicalId":279385,"journal":{"name":"Topical Meeting on Signal Recovery and Synthesis with Incomplete Information and Partial Constraints","volume":"32 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131126445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Stable, non-iterative, object reconstruction from incomplete data using prior knowledge 稳定的，非迭代的，利用先验知识从不完整的数据重建对象

Topical Meeting on Signal Recovery and Synthesis with Incomplete Information and Partial Constraints Pub Date : 1900-01-01 DOI: 10.1364/srs.1983.wa9

A. M. Darling, T. Hall, M. Fiddy

引用次数: 3

Mathematical Results of the Phase Retrieval Problem for Bandlimited Functions of Several Variables 多变量限带函数的相位恢复问题的数学结果

Topical Meeting on Signal Recovery and Synthesis with Incomplete Information and Partial Constraints Pub Date : 1900-01-01 DOI: 10.1364/srs.1983.tha4

W. Lawton

引用次数: 1

Linear Estimation with a Size Constraint 具有大小约束的线性估计

Topical Meeting on Signal Recovery and Synthesis with Incomplete Information and Partial Constraints Pub Date : 1900-01-01 DOI: 10.1364/srs.1983.fa5

M. J. Lahart

引用次数: 0

Matched Image Formation and Restoration System* 匹配图像生成与恢复系统*

Topical Meeting on Signal Recovery and Synthesis with Incomplete Information and Partial Constraints Pub Date : 1900-01-01 DOI: 10.1364/srs.1983.wa7

W. Cathey, B. Frieden, W. Rhodes, C. Rushforth

引用次数: 0

Geometric Deconvolution of Artifacts in Limited View Computed Tomography 有限视图计算机断层扫描中伪影的几何反卷积

Topical Meeting on Signal Recovery and Synthesis with Incomplete Information and Partial Constraints Pub Date : 1900-01-01 DOI: 10.1364/srs.1983.fa2

R. Rangayyan, R. Gordon

引用次数: 0

Reconstruction in Electron Microscopy 电镜重建

Topical Meeting on Signal Recovery and Synthesis with Incomplete Information and Partial Constraints Pub Date : 1900-01-01 DOI: 10.1364/srs.1983.tha16

W. O. Saxton

引用次数: 0

Four Models for the Band-Limited Signal Extrapolation Problem 带限信号外推问题的四种模型

Topical Meeting on Signal Recovery and Synthesis with Incomplete Information and Partial Constraints Pub Date : 1900-01-01 DOI: 10.1364/srs.1983.wa2

Thomas S. Huang, J. S. L. Sang

引用次数: 1