Demonstrating Palm Touch: The Palm As an Additional Input Modality on Commodity Smartphones

Abstract

T ouchscreens are the most successful input method for smartphones. Despite their flexibility , touch input is limited to the location of taps and gestures. We present PalmT ouch, an additional input modality that differentiates between touches of fingers and the palm. T ouching the display with the palm can be a natural gesture since moving the thumb towards the device’s top edge implicitly places the palm on the touchscreen. We developed a model that differentiates between finger and palm touch with an accuracy of 99.53 % in realistic scenarios. In this demonstration, we exhibit different use cases for PalmT ouch, including the use as a shortcut and for improving reachability . In a previous evaluation, we showed that participants perceive the input modality as intuitive and natural to perform. Moreover, they appreciate PalmT ouchas an easy and fast solution to address the reachability issue during one-handed smartphone interaction compared to thumb stretching or grip changes.