A shape-free, designable 6-DoF marker tracking method

Markers are widely used for camera-based interaction. Yet, most of the marker tracking methods have considerable limitations in shapes and designs; they are not usually visually meaningful to the users. Such an issue on visually communicative designs can be very important to provide visual cues in a mobile/pervasive environment where a user must first notice a marker and understand its meaning before initiating interaction, unlike in an immersive environment with a head-mounted-display that keeps displaying information on the detected markers.