1. An electronic device comprising: a camera oriented to capture images across a surface; and a processing unit configured to perform operations comprising: accessing an image captured by the camera; identifying multiple regions that are defined within a field of view of the camera and that each correspond to one interface control positioned on the surface; determining, from among the multiple defined regions, a region in which an object detected within the accessed image is positioned; determining user input based on the one interface control that corresponds to the determined region; and controlling an application based on the determined user input.