PICaFACE

Taking pictures with the mobile device can get difficult if only one hand is available for the interaction, especially if the device is very large and the user wants to take quick snapshots. PICaFACE, a camera application prototype, introduces new interaction techniques, which integrate the performance of facial expressions to simplify the user’s single-finger interaction. The zoom mode is triggered by pursing the lips and widening the mouth or tilting the head forwards and backwards. The release function is fired by raising the eyebrows or opening the mouth. The zoom center can always be defined with one touch onto the screen, which is simulated with a mouse click in PICaFACE. With a small user study the different zoom and release gestures have been analysed and compared to get hints about how efficient, intuitive, comfortable and accepted each technique turns out to be for the users. As a result, mouth gestures were generally perceived as entertaining but not as very advantageous to improve the one-handed process.