Assessment of optical see-through head mounted display calibration for interactive augmented reality

Interaction in Augmented Reality environments requires the precise alignment of virtual elements added to the real scene. This can be achieved if the egocentric perception of the augmented scene is coherent in both the virtual and the real reference frames. To this aim, a proper calibration of the complete system, composed of the Augmented Reality device, the user and the environment, should be performed. Over the years, several calibration techniques have been proposed, and objectively evaluating their performance has shown to be troublesome. Since only the user can assess the hologram alignment fidelity, most researchers quantify the calibration error with subjective data from user studies. This paper describes the calibration process of an optical see-through device, based on a visual alignment method, and proposes a technique to objectively quantify the residual misalignment error.