Gunslinger: Subtle Arms-down Mid-air Interaction

We describe Gunslinger, a mid-air interaction technique using barehand postures and gestures. Unlike past work, we explore a relaxed arms-down position with both hands interacting at the sides of the body. It features "hand-cursor" feedback to communicate recognized hand posture, command mode and tracking quality; and a simple, but flexible hand posture recognizer. Although Gunslinger is suitable for many usage contexts, we focus on integrating mid-air gestures with large display touch input. We show how the Gunslinger form factor enables an interaction language that is equivalent, coherent, and compatible with large display touch input. A four-part study evaluates Midas Touch, posture recognition feedback, pointing and clicking, and general usability.