Comparison method to differentiate between painted objects using polychromatic X-rays.

X-radiography using the bremsstrahlung of a commercial broad spectrum X-ray source was used to quantify the differences and relationships between complex samples of unknown composition. The samples examined were painted and glazed ceramic mugs. The resulting pseudo-signatures were grey-level transmission spectra which can be usefully compared over a range of acceleration potential settings from 40 to 95 kV, taken at 1 kV intervals. These data are extracted from stacks of registered field-flattened X-ray images. It is shown that it is possible to differentiate between transmission spectra of the samples by concentrating mainly on the paint layers. [ABSTRACT FROM AUTHOR]