Tag-based vision: assisting 3D scene analysis with radio-frequency tags

In image sensing and processing, ambiguities arise when only one source of information is used. Thus, 3D object recognition and localization is a difficult task when using intensity image as single input. This paper presents a machine vision system that uses a Radio Frequency (RF) Tag device to identify objects prior to locating them visually. The tag system consists of a tag reader that can interrogate, and receive radio signals from, tags attached on objects and characterizing them. Laying the basis of an object model database shared on a network, we perform a knowledge-based recognition task where the information retrieved from the database query serves as a prior knowledge. The recognition algorithm used is a matching with projective invariants. We describe how this system can be used for efficient object registration and how the concept of integrated tag based systems can provide new insights in image processing and machine vision.