Patent ID: 8116431

Claim:
A method of inspecting a vehicle comprising: acquiring at a computer a dual-energy x-ray image of the vehicle, wherein the dual-image x-ray image consists of a plurality of pixels, each of said plurality of pixels consisting of measured data for each of the dual energies and some number of the plurality of pixels including measured data for steel objects in the vehicle; calculating at the computer a steel suppressed image wherein a value for steel in each of the some number of the plurality of pixels is removed; calibrating at the computer the steel suppressed image wherein each of the plurality of pixels is a direct measure of non-steel objects in the vehicle; determining at the computer boundaries for one or more non-steel objects in the vehicle; calculating at the computer a mass for each non-steel object from its boundaries and the calibrated steel suppressed image; comparing at the computer the calculated mass for each non-steel object with a predetermined threshold; and triggering by the computer an alarm when the comparison for one ore more non-steel objects exceeds the predetermined threshold.