TOMOGRAPHIC FILTERS IN IMAGE RECONSTRUCTION

Abstract

In this report, we have studied in details about the different computer tomographic. imaging techniques. Tomographic imaging refers to the reconstruction of two-dimensional cross-sectional images of an object from their projections with the use of X-rays. The technique is developed based on the Fourier Slice Theorem and is implemented with the filtered backprojection algorithm. We have used two algorithms for carrying out tomographic imaging - the parallel beam and the fan beam reconstruction algorithm. Some sinograms are created for a Shepp-Logan Head Phantom image and then reconstructed these images from the projections using backprojection, filtered backprojection. Some filters were used for both filtered versions of the reconstruction techniques. The application of these algorithms has been simulated by the development of two MATLAB models In this work, different projection methods for image reconstruction from fan projections were carried out. To this goal, a geometrical relation between parallel and fan beam projections was first formulated. This geometrical relation provided the basis for the reconstruction of an image from its fan projection using conventional reconstruction methods, such as filtered backprojection.