Active X-ray Testing of Complex Objects Vladimir Riffo and Domingo Mery Department of Computer Science – Pontificia Universidad Catolica de Chile vriffo1@uc.cl, dmery@ing.puc.cl Abstract X-ray testing of complex objects –such as luggage screening at airports– is usually performed manually. This is not always effective, since it depends strongly on the pose of the objects of interest (target objects), occlusion and human capabilities as well. Additionally, certain target objects are difficult to be detected using only one viewpoint. For this reason, we developed an active X-ray testing framework that is able to adequate the viewpoint of the target object in order to obtain better X-ray images to analyze. The key idea of our method is to adapt auto- matically the viewpoint of the X-ray images in order to project the target object in poses where the detection performance should be higher. Thus, the detection inside of complex objects can be performed in a more effective way. Using a robotic arm and a semi-automatic manipulator system, the robustness and reliability of the method have been verified in the automated de- tection of razor blades located inside of nine different objects showing promising preliminary results: in 130 experiments we were able to detect 115 times the razor blade with 10 false alarms, achieving recall of 89% and precision of 92%. Keywords: X-ray inspection, baggage screening, framework, SIFT, active vision, target object detection. 1 Introduction It is well known that X-ray inspection can be performed by human inspectors or automatic systems. Although humans in many cases can do the job better than machines, they are slower 1