Fan-beam geometry based inversion algorithm in computed tomography (CT) for imaging of composite materials

The investigation is concerned first with reconstruction of the density function of an object from computed tomography data. The projection (Fourier Slice) theorem is discussed for fan-beam geometry. A rebinning algorithm, based on the slant stacking approach, is introduced in order to transform fan-beam geometry data into its parallel-beam counterpart. The density function is reconstructed using a filtered back-projection algorithm. The sampling criteria for fan beam computed tomography are also derived. The MATLAB package has been utilized to implement these algorithms for the simulation of Shepp–Logan head phantom and implementation of the discrete normal Radon transform based on fan-beam geometry. The reconstruction of transverse cross-sectional micro-structures of fiber reinforced composite material test specimens has also been discussed. In addition, the MATLAB package has been utilized to demonstrate the image reconstruction of the cross-section of a two-phase composite material using parallel beam geometry (Radon transform).