Local algorithms in exterior tomography
نویسنده
چکیده
Exterior tomographic data are taken over lines outside a central region, and such data occur in the industrial nondestructive evaluation of large objects such as rockets. We explain, using microlocal analysis, which singularities are well reconstructed from exterior data, and we explain how this phenomenon is reflected in the singular value decomposition for the exterior transform [E.T. Quinto, Singular value decompositions and inversion methods for the exterior Radon transform and a spherical transform, J. Math. Anal. Appl. 95 (1983) 437–448]. We extend Lambda Tomography to exterior data and to limited angle exterior data. The algorithm is tested on industrial data from Perceptics, Inc. © 2005 Elsevier B.V. All rights reserved.
منابع مشابه
Accuracy improvement of Best Scanline Search Algorithms for Object to Image Transformation of Linear Pushbroom Imagery
Unlike the frame type images, back-projection of ground points onto the 2D image space is not a straightforward process for the linear pushbroom imagery. In this type of images, best scanline search problem complicates image processing using Collinearity equation from computational point of view in order to achieve reliable exterior orientation parameters. In recent years, new best scanline sea...
متن کاملExterior and limited-angle tomography in non-destructive evaluation
The author’s exterior reconstruction algorithm is used to reconstruct two high-quality finely sampled exterior tomographic data sets from a high-resolution cone beam computed tomography scanner developed by Perceptics, Inc. One data set is complete exterior data and the other data set is limited-angle exterior data with an angular range of 135◦. The author adapts his algorithm to reconstruct th...
متن کاملDose Assessment in Computed Tomography Examination and Establishment of Local Diagnostic Reference Levels in Mazandaran, Iran
Background: Medical X-rays are the largest man-made source of public exposure to ionizing radiation. While the benefits of Computed Tomography (CT) are well known in accurate diagnosis, those benefits are not risk-free. CT is a device with higher patient dose in comparison with other conventional radiation procedures. Objective: This study is aimed at evaluating radiation dose to patients from ...
متن کاملTracking boundary movement and exterior shape modelling in lung EIT imaging.
Electrical impedance tomography (EIT) has shown significant promise for lung imaging. One key challenge for EIT in this application is the movement of electrodes during breathing, which introduces artefacts in reconstructed images. Various approaches have been proposed to compensate for electrode movement, but no comparison of these approaches is available. This paper analyses boundary model mi...
متن کاملFiltered backprojection method and the interior problem in 2D tomography
We address here the interior problem in local tomography, by means of filtered backprojection (FBP). This algorithm, traditionally used in the context of complete data, is usually not considered as valuable for the interior problem. However, in this article, we prove that as well as more sophisticated methods, the FBP algorithm ensures that the difference between the original and the reconstruc...
متن کامل