ShadowPuppets: Supporting Collocated Interaction with Mobile Projector Phones Using Hand Shadows

摘要

Pico projectors attached to mobile phones allow users to view phone content using a large display. However, to provide input to projector phones, users have to look at the device, diverting their attention from the projected image. Additionally, other collocated users have no way of interacting with the device. We present ShadowPuppets, a system that supports collocated interaction with mobile projector phones. ShadowPuppets allows users to cast hand shadows as input to mobile projector phones. Most people understand how to cast hand shadows, which provide an easy input modality. Additionally, they implicitly support collocated usage, as nearby users can cast shadows as input and one user can see and understand another user's hand shadows. We describe the results of three user studies. The first study examines what hand shadows users expect will cause various effects. The second study looks at how users perceive hand shadows, examining what effects they think various hand shadows will cause. Finally, we present qualitative results from a study with our functional prototype and discuss design implications for systems using shadows as input. Our findings suggest that shadow input can provide a natural and intuitive way of interacting with projected interfaces and can support collocated collaboration.