Registration is a crucial task in a see-through augmented reality (AR) system. The importance stems not only from the fact that registration requires careful calibration but also from the necessity that any calibration procedure should take into account the users. [14] proposed a general method for calibrating a see-through device based on dynamic alignment of virtual and real points. Although a powerful tool, our experiments showed that users find alignment of many points overwhelming.

We introduce improvements to simplify the calibration process and increase the success rate. We first identified the causes why calibration parameters differ from user to user that can be prevented by adopting particular configurations for the tracker sensor and the display. This allowed us to re-use the existing calibrations. Furthermore, we have introduced a simpler model for the calibration that requires less number of user inputs, typically four, to calibrate the system.