X-RAY BACKSCATTER IMAGING SYSTEM INCLUDING MOVING BODY TRACKING ASSEMBLY

A pencil beam of X-rays is scanned over the surfaces of the body of a person being examined as the person walks through the scanning apparatus. Specifically, a tracking assembly is employed to rotate the scanning plane through a tracking angle and in a direction progressing from the entrance to the exit of the portal, through which the person passes, in order to substantially track the person or body as it moves with respect to the system from the entrance to the exit X-rays that are scattered or reflected from the subject's body are detected by a detector assembly. The signal produced by this scattered X-ray detector in then used to modulate an image display device to produce an image of the subject and any concealed objects carried by the subject. The detector assembly is constructed in a configuration to automatically and uniformly enhance the image edges of low atomic number (low Z) concealed objects to facilitate their detection. A storage means is provided by which previously acquired images can be compared with the present image for analyzing variances in and similarities with the present image, and provides means for creating a generic representation of the body being examined while suppressing anatomical features of the subject to minimize invasion of the subject's privacy.