The author addresses the problems of imagereconstruction in fan beam straight-path tomography from complete and incompletedata. A method for restoring the parallel beam projections of an object from its fan beam pro...
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The author addresses the problems of imagereconstruction in fan beam straight-path tomography from complete and incompletedata. A method for restoring the parallel beam projections of an object from its fan beam projections is introduced. The scheme uses FFT routines. This approach reduces the required amount of the collected fan beam by half. Also, a noniterative method of imagereconstruction, when arbitrary segments of the object projections cannot be detected, is presented. The technique exploits the functional properties of the object projections, in conjunction with a priori information available about the test object, to restore the unknown data.
A study of the direct Fourier method for the three-dimensional reconstruction of objects from their two-dimensional projection images has been carried out using computer-generated images. The existence of missing info...
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ISBN:
(纸本)0444878475
A study of the direct Fourier method for the three-dimensional reconstruction of objects from their two-dimensional projection images has been carried out using computer-generated images. The existence of missing information in the real input data is discussed, and point spread functions corresponding to some experimental data acquisition procedures are calculated. Several three-dimensional reconstructions of the model object are obtained and compared to real datareconstructions. Useful criteria for assessing the quality and the correct interpretation of the experimentally reconstructed images are deduced.
This paper addresses the problems of imagereconstruction in fan beam straight-path tomography from complete and incompletedata. A method for restoring the parallel beam projections of an object from its fan beam pro...
详细信息
This paper addresses the problems of imagereconstruction in fan beam straight-path tomography from complete and incompletedata. A method for restoring the parallel beam projections of an object from its fan beam projections is introduced. The scheme utilizes FFT routines for this purpose. It is shown that the approach reduces the required amount of the collected fan beam data by half. Moreover, a noniterative method of imagereconstruction, when arbitrary segments of the object projections cannot be detected, is presented. The technique exploits the functional properties of the object projections, in conjunction with a priori information available about the test object, to restore the unknown data.
Spotlight-mode synthetic aperture radar (SAR) imaging has a close resemblance to tomographic imagereconstructionfromincomplete view data. A new algorithm (PRDF), designed for reconstructing tomographic imagery from...
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Spotlight-mode synthetic aperture radar (SAR) imaging has a close resemblance to tomographic imagereconstructionfromincomplete view data. A new algorithm (PRDF), designed for reconstructing tomographic imagery fromincomplete view data, is described. The results of applying the PRDF algorithm to reconstruct a human thorax cross-section from simulated X-ray projection data are furnished. An algorithm which is basically a special case of PRDF is suggested for spotlight-mode SAR imaging.
The restoration or reconstruction of an object distribution or image when only limited discrete Fourier data are available is a common problem in many disciplines. Such problems are known to be ill-posed but regularis...
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The restoration or reconstruction of an object distribution or image when only limited discrete Fourier data are available is a common problem in many disciplines. Such problems are known to be ill-posed but regularisation theory defines a set of admissible or approximate estimates for the image by imposing constraints on these estimates. Even in the absence of noise, incomplete sampled data means that there are infinitely many image estimates consistent with, for example, the available Fourier data and the image support. To resolve these ambiguities prior knowledge is used to reduce the class of allowed solutions and to design a model and an optimality criterion.
An estimation approach to three dimensional reconstructionfrom projections, with incomplete and very noisy data, is suggested. Using a stochastic dynamic model for the object of interest in the probed domain, the rec...
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An estimation approach to three dimensional reconstructionfrom projections, with incomplete and very noisy data, is suggested. Using a stochastic dynamic model for the object of interest in the probed domain, the reconstruction problem is reformulated as a nonlinear state estimation problem of small dimensionality, and an approximate MMSE globally optimal algorithm for its solution is presented. The algorithm, which is recursive in a hybrid frequency-space domain, operates directly on the Fourier transformed projection data, eliminating altogether the attempt to invert the projection integral equation. The computational requirements compare favorably with those of conventional reconstruction procedures, which fail in the limited and noisy data case.
The authors are interested in the reconstruction of 3-D objects from various sources of incompletedata as well as apriori knowledge about the object under reconstruction. As data sources use is made of conventional X...
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The authors are interested in the reconstruction of 3-D objects from various sources of incompletedata as well as apriori knowledge about the object under reconstruction. As data sources use is made of conventional Xray projections as well as CAT scans perpendicular to the Xray planes. These data sources were chosen because they are complementary to each other, in the sense that information not found in one set can be found in the other.
The authors are interested in the reconstruction of 3-D objects from various sources of incompletedata as well as apriori knowledge about the object under reconstruction. As data sources use is made of conventional X...
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The authors are interested in the reconstruction of 3-D objects from various sources of incompletedata as well as apriori knowledge about the object under reconstruction. As data sources use is made of conventional Xray projections as well as CAT scans perpendicular to the Xray planes. These data sources were chosen because they are complementary to each other, in the sense that information not found in one set can be found in the other.
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