Methods for assigning attributes to an image of an object scanned with ionizing electromagnetic radiation

A method for assigning an attribute to x-ray attenuation comprising:

• scanning in an x-ray scanning device, first and second reference materials each having known atomic composition, known dimensions and known orientation in the x-ray scanning device, the x-ray scanning device emitting x-rays which pass through the first reference material with first reference material path lengths and through the second reference material with second reference material path lengths, the x-rays being detected by an array of detectors to provide a plurality of dual-energy attenuation images each having dual-energy x-ray attenuation information;
• associating the dual-energy x-ray attenuation information for each pixel in the dual-energy attenuation images with each of the first reference material path lengths and the second reference material path lengths;
• and,
• expressing collectively each of the first reference material equivalent path lengths and the second reference material equivalent path lengths as a function of the associated dual-energy x-ray attenuation information to define dual-energy attenuation surfaces upon which may be imposed dual-energy attenuation values to determine corresponding first reference material equivalent path lengths and second reference material equivalent path lengths.