HeadZoom: Hands-Free Zooming and Panning for 2D Image Navigation Using Head Motion

Abstract: We introduce \textit{HeadZoom}, a hands-free interaction technique for navigating two-dimensional visual content using head movements. The system enables fluid zooming and panning by only using real-time head tracking. It supports natural control in applications such as map exploration, radiograph inspection, and image browsing, particularly where physical interaction is limited. We evaluated HeadZoom in a within-subjects user study comparing three interaction techniques-Static, Tilt Zoom, and Parallel Zoom-across spatial, error, and subjective metrics. Results show that Parallel Zoom significantly reduced total head movement compared to Static and Tilt modes. Users reported significantly lower perceived exertion for Parallel Zoom, confirming its suitability for prolonged or precision-based tasks. By minimising movement demands while maintaining task effectiveness, HeadZoom advances the design of head-based 2D interaction in VR, creating new opportunities for immersive, accessible, and hands-free systems for image exploration.