Mixed-Resolution Gesturing on Interactive Surfaces

An affordance of multi-touch tablet computers and interactive surfaces, such as the Apple iPad and Microsoft Surface, is the ability to allow for free form input. However, sketching on multi-touch tablets is challenging due to the need to switch between defining coarse and fine features of a drawing. Additionally, drawing at a small scale introduces occlusion and inaccuracy as a result of the fat finger problem. This project outlines our attempts to address the fat finger problem by efficiently supporting mixed-resolution sketching for multi-touch devices.

ZoomPointing Revisited: Supporting Mixed-resolution Gesturing on Interactive Surfaces

Matei Negulescu, Jaime Ruiz, Edward Lank

In this work we explore bi-manual interaction as a potential solution to the fat finger problem in the form of a transient zooming technique we call ZoomSketch. ZoomSketch uses the dominant hand to specify the focal point and the non-dominant hand to zoom and pan (Figure 1c). The non-dominant hand specifies the magnitude and the direction of expansion. Transformations to the view (e.g. zooming, panning) are reset when there are no fingers active on the screen.

Figure 1. Three methods of supporting mixed-resolution drawing on interactive surfaces: (a) Pinch-based zoom; (b) Widget – a bi-manual technique where one hand is used to select the target and the other is used to zoom through a widget; and ZoomSketch (c), a hybrid technique where one hand is used to set the target while the other locally specifies the zoom magnitude

A think-aloud study that compared our design to a bi-manual widget interaction (Figure 1b) and the classic pinch-based interaction (Figure 1a), suggests that ZoomSketching offers benefits in terms of performance degree of and control. Finally, the transient nature of view transformations appears to impact not only performance, but workflow, focus of interaction, and subjective quality of results by providing a constant overview. ZoomSketch showed significant promise for mixed-resolution sketching on interactive surfaces.