Research On The Geometry And Density Information Of The Object Based On X-ray Transillumination Images

Security equipment has been developed maturely by now and is widely used in airports, railways, docks, highways and other major transportation venues, postal services, conferences, special departments where need security check. It provides more security for our lives.Traditional X-ray security instruments screen objects using X-ray transmission imaging technology. Make digital image processing to the obtained image data, then set the classification threshold region by the material classification test, to define organic, inorganic, and mixture, and distinguish the risk products. This technology can effectively identify dangerous goods, but with advances in technology, a variety security equipments with more powerful function and more accurate recognition appeared. Effective atomic number and the eigenvalues R of material properties can’t meet current safety inspection requirements. Therefore, we must make further research on the traditional screening instrument to obtain more key information about the seized objects to address the impact of new technologies.In this paper, we chose DTSCAN6550produced by Northeastern University DiTai Co., Ltd for the study. First, made a brief introduction about the current field of security devices and the advanced technology; then outlined the basic principles of the X-ray detection technology, and some common X-ray detection systems; the next chapter began the key parts, namely, extracted the edge feature by edge detections, and calculated outside geometry about seized objects, combining with the principle of object detectors and imaging principle, which used Matlab and Mathcad to calculate; next according to the experimental data calculated mass absorption coefficient of common substances and dangerous goods, then obtained X-ray transmission thickness based on the the geometry calculations, so we could obtained density values according to the formula, thus we could determine the material properties more accurately; defined the eigenvalue of density information, built density information database; final part was summary of research content.