%0 Thesis
%T Use of Projection and Back-projection Methods in Bidimensional Computed Tomography Image Reconstruction
%A Jorge Bernal
%D 2009
%C Barcelona, Spain
%C Computer Vision Center
%F Jorge Bernal2009
%O MV;
%O exported from refbase (http://refbase.cvc.uab.es/show.php?record=1693), last updated on Fri, 14 Mar 2014 15:51:17 +0100
%X One of the biggest drawbacks related to the use of CT scanners is the cost (in memory and in time) associated. In this project many methods to simulate their functioning, but in a more feasible way (taking an industrial point of view), will be studied.The main group of techniques that are being used are the one entitled as ’back-projection’. The concept behind is to simulate the X ray emission in CT scans by lines that cross with the image we want to reconstruct.In the first part of this document euclidean geometry is used to face the tasks of projec- tion and back-projection. After analysing the results achieved it has been proved that this approach does not lead to a fully perfect reconstruction (and also has some other problems related to running time and memory cost). Because of this in the second part of the document ’Filtered Back-projection’ method is introduced in order to improve the results.Filtered Back-projection methods rely on mathematical transforms (Fourier, Radon) in order to provide more accurate results that can be obtained in much less time. The main cause of this better results is the use of a filtering process before the back-projection in order to avoid high frequency-caused errors.As a result of this project two different implementations (one for each approach) had been implemented in order to compare their performance.
%K Projection
%K Back-projection
%K CT scan
%K Euclidean geometry
%K Radon transform
%9 theses
%9 Masters thesis
%U http://refbase.cvc.uab.es/files/Ber2009.pdf