Colored visual tags: a robust approach for augmented reality

This paper presents a robust method for fast Visual Tags reading, suitable for Augmented Reality (AR) environments. Tag detection is based on well known tools of image-processing, but their combination, together with the use of colored markers, allows a robust recognition even with lowcost CMOS or CCD cameras and in poorly illuminated environments. In particular the color mix and the structure of the tag are quite unusual in common environments and can be easily detected with color filtering and geometric analysis. The proposed tag carries binary information encoded in its structure: in the presented implementation a 32-bit code with 12 parity bits is encoded in the tag but extensions to longer codes can be easily devised.