This paper is an extended abstract of the doctoral thesis 1 which attempts to fill the knowledge gap between user understanding and available Augmented Reality (AR) technology, a result of the ...general lack of user studies in AR and high-pace technology-driven AR development. The thesis pursues this goal by: (i) reviewing perceptual issues that relate to handheld AR in order to identify usability issues; (ii) reviewing handheld AR system utility in order to propose utility improvements; (iii) conducting empirical user studies to explore identified usability issues; (iv) designing, building and evaluating solutions that will enhance handheld AR utility and usability.
Typically handheld AR systems utilize a single back-facing camera and the screen in order to implement device transparency. This creates the dual-view problem a consequence of virtual transparency ...which does not match true transparency - what the user would see looking through a transparent glass pane. The dual-view problem affects usability of handheld AR systems and is commonly addressed though user-perspective rendering solutions. Whilst such approach produces promising results, the complexity of implementing user-perspective rendering and the fact it does not solve all sources that produce the dual-view problem, means it only ever addresses part of the problem. This paper seeks to create a more complete solution for the dual-view problem that will be applicable to readily available handheld-device. We pursue this goal by designing, implementing and evaluating a novel interaction paradigm we call `contact-view'. By utilizing the back and front-facing camera and the environment base-plane texture - predefined or incrementally created on the fly, we enable placing the device directly on top of the base-plane. As long as the position of the phone in relation to the base-plane is known, appropriate segment of the occluded base-plane can be rendered on the device screen, result of which is transparency in which dual-view problem is eliminated.
