The cylinder algorithm. An efficient reconstruction algorithm for the 3D x-ray computed tomography (3D-CT) in NDT

The development of production techniques which meet the high requirements of defectless production is decisive to ensure sufficient reliability and high quality of the products. Nondestructive testing can contribute an essential part to optimize production process for high quality products. In some materials (e.g. ceramics) small defects in the mu m range can lead to failure. Therefore nondestructive testing methods with a high spatial resolution capability are required. The 3D X-Ray Computed Tomography (3D-CT), presented in this contribution, inspects the whole volume and provides images with the necessary spatial resolution. Besides the principles of 3D-CT, the set-up of our system we will mainly focus in this paper to the development of a new efficient 3D reconstruction algorithm for cone beam projections which is based on the well known Feldkamp algorithm. The main difference between our algorithm and the Feldkamp algorithm is that the volume of the obfect under inspection is recon s reconstructed in cylinder coordinates versus cartesian coordinates in the Feldkamp algorithm. The new algorithm is up to five times faster than the Feldkamp algorithm. The new algorithm is up to five times faster than the Feldkamp algorithm and present some results of applications which will demonstrate the advantage of our 3D-CT system with the new 3D reconstruction algorithm.