mIDoT: Micro identifier dot on things — A tiny, efficient alternative to barcodes, tags, or marking for industrial parts traceability
Rui Ishiyama, Yuta Kudo, Toru Takahashi · 2016
We propose a novel, efficient way to identify things to which it is difficult to attach identifiers such as markers, barcodes and RFID tags. With our proposed method, a dot of metallic or glitter ink is attached onto an object and is identified as unique by matching a microscopic image of the dot with a database. The ink is an inexpensive consumer product. It is a mixture of a basic ink with micro particles that form random irregularities on the surface. Since the irregularities naturally become unique for each dot, any dot is identified by matching its image features. Consequently, the dot works as a unique identifier of an object, and this is useful as an alternative to the barcode, RFID tag, or marking. Called "mIDoT," this identification framework enables tiny parts to be traceable and the manufacturing process to be observed in detail. The proposed method uses the modified "FIBAR" lighting method to capture micro surface irregularities as robust image features like fingerprints, enabling the robust image matching required for large-scale identification. In experiments, 1,172 dots were uniquely identified with zero error, which opens the door to real applications such as those in which millions of parts are identified. Finally, we demonstrate a prototype of a traceability system for tiny electric parts.