Section: New Results

Transfer functions for subpixel interaction

Participants : Jonathan Aceituno, Géry Casiez [correspondant] , Nicolas Roussel.

The current practice of using integer positions for pointing events artificially constrains human precision capabilities (Figure 1 ). The high sensitivity of current input devices can be harnessed to enable precise direct manipulation "in between" pixels, called subpixel interaction. In [23] , we provide a detailed analysis of subpixel theory and implementation, including the critical component of revised control-display gain transfer functions. A prototype implementation is described with several illustrative examples. Guidelines for subpixel domain applicability are provided and an overview of required changes to operating systems and graphical user interface frameworks are discussed.

Figure 1. Input mappings: (a) currently, human movements are discretized by mouse sensitivity, then again by display density: data points "in between" pixels like 'C' are unreachable; (b) a subpixel mapping discretizes human movements by mouse sensitivity only, for precise data manipulation (left). Four zones of applicability for subpixel and custom transfer functions (see text for description) (right).