Research Of Optimize Reconstruction Method Of Cone X-ray Projection By Useing Relative Density

In the last several decades, X-ray security checking equipments have beenwidely applied in security checking at major entrances and exits. This is a equipmentwhich can rapidly check luggage because of the penetration capability of X-ray.Low-cost, low-dose and non-contact is the advantage of them. But the securitychecking equipments also have some defects. The most of them only canreconstruction in two dimensionality and has low resolving power. They can detectthe substance which absorb the X ray severely such as metal easily. But thesubstance which absorb the X ray slightly is hardly detected. So ,this paper wantadvance some new idea to resolve the problems by the research on reconstructionarithmetic of X ray .Because of the immanent defects of the two dimensional reconstruction, We cannot resolve them by useing a arithmetic. The three-dimensional scanning CT is abetter choose because of its strong advantages. Because of the particularity ofsecurity checking,the speed of reconstruction must quickly. But the data of threedimensional reconstruction is hugeness and the arithmetic is complexity. So,it has alow speed. This paper try to devolve this problem.This paper discuss some classical arithmetic and analyse some new though. Themost time spend on filter back projection arithmetic is spending on the backprojection process. Makeing use of the particularity of security checking, this paperadvance a high-speed back projection arithmetic aim at special density detected. Ituse the image division and patten recognition method to find the area which weinterested on the image which is reconstructed by imperfect data. It can improve thespeed of reconstructed and the reconstruction of the area which we interested is alsoin good condition. Then, this paper discuss some method which can improve thespeed of FDK arithmetic and use them with the method advance before to make anew arithmetic and produce a computer model of it. The result of experiment provethat the speed is more quickly and the reconstruction of the area which we interestedis good enough.