Photographic Comparison for Item Tagging and Tamper Indication

Intrinsic characteristic properties of any item may be used to label or tag the item. Highresolution photographic recording and comparison may be used to (1) record intrinsic characteristics without physical contact and/or (2) detect change to an item through comparison to earlier photographs. Intrinsic tagging could monitor a sufficiently unique item for some classes of tampering without the need for physical contact with the item. Comparing photographs using blink or flicker comparison allows examination of images too complex for unaided visual examination. Applying blink comparison to inspection applications has been difficult since the technique relies upon images with well-matched fields of view. The Change Detection System (CDS), produced at the Idaho National Engineering and Environmental Laboratory, solves this problem by transforming the images to match common features well enough for successful blink comparison. The CDS enables high-quality inspection even with hand-held cameras. Combining CDS with a high-end digital camera results in a highly capable toolkit to inspect items and detect tampering with or counterfeiting of seals. For example, these tools allow fine details of handwritten signatures to become an intrinsic feature. Several examples are presented in this paper as well as results from an example implementation of an inspection system.