The Study Of CT Algorithm Based On The Direct Characteristic Reconstruction

Computed tomography (CT) technology is Image Reconstruction from projection. This thesis taking CT algorithm which is the core of CT technology for research object. From the theory research and engineering application perspective, two criteria were given to judge the CT performance:"the best"and"the most useful". Based on these two criteria, makes rebuliet the image characteristics (such as flaws, outline, etc)for purpose, make use of some properties of Radon transformation,we study CT technique based on the direct characteristic reconstruction, directly reconstruct the characteristics of image,that can highlights characteristic information of we interested in detection object without sacrificing too much in the background image resolution of circumstances, better to improve the overall detection system.In this paper, First introduced the basic theory of image reconstruction of Radon transformation and the central slice theorem and filter back-projection algorithm, abstract on the image reconstruction to the math problem which used line integral value determine integrand, analysis and study image reconstruction on the view of mathematical orientation. On this basis, Considering at the side of"the most useful", the elementary concepts of CT lgorithm based on the direct characteristic reconstruction were given in the paper, then we prove one of important properties of Radon transformation– convolution distribution and further systematically deduced the basic formulae of the reconstruction.After all,we theoretically analyses the advantages of CT algorithm based on the direct characteristic reconstruction using the optimization design concept. Combined with engineering application,we makes direct reconstruction edge character for example to study the Realizing technology of the CT algorithm based on the direct characteristic reconstruction, so the correctness of the algorithm and it's advantages was proved at the same time. Finally we study on the multi-characteristic CT reconstruction based on EMD method for seek a more general CT algorithm based on the direct characteristic reconstruction. It achieved many frequency characteristics the denoising reconstruction.