Quantitative radiography is an imaging technique that uses electromagnetic radiation, such as X-rays, to gather quantitative data about the interior of nontransparent objects that vary in density and composition. For example, radiography is particularly helpful when reconstructing objects composed of multiple materials, such as different types of metal. In order to generate these images, most high-energy technologies pulse X-rays through the “scene” in question; objects in the scene absorb some of the rays, while a scintillator – which measures the strength of the passing X-rays – collects the rest and fluoresces (emits visible light) in response to the collected rays. Possible scenes include parts of the human body, thermal explosions, nuclear testing sites, and other applications of national security. The resulting images directly measure the intensity of visible light, yielding information about the objects’ internal structure.