Augmented X-rays: New functionalities for High energy X-rays Cargo scanner

X-ray radioscopy at high energies (MeV) is a widely used technique for non-destructive inspection of cargo containers and trucks at ports and borders. Dual-energy imaging is an established method for cargo material discrimination, that works by estimating the average effective atomic number of penetrated objects along each X-ray path, based on the energy dependent mass attenuation coefficient of materials. However, due to 2D nature of the radioscopy image, it is currently difficult to understand how the objects are positioned in the cargo depth and material discrimination interest is limited when objects of different natures are superimposed along X-ray paths. In this article, we describe four totally new imaging functionalities which have been developed and validated by end-users during field tests. These functionalities, under a generic name Augmented X-rays (AXR), are based on the use of multi-column detectors (called Matrix detector) and new algorithms for the material discrimination. They are comprised of in-depth information, image stabilization, wall removal (removing of metallic objects) and de-overlapping of material discrimination. These functions help in pushing the current 2D cargo inspection close to pseudo 3D by localizing on which depth planes are the objects (either close to the accelerator or the detector) and extends the usefulness of material discrimination by discriminating objects one-by-one, helping ease the identification of low atomic number objects (explosives, drugs, cigarettes…).