1. A method, comprising: performing by at least one processor: controlling a projector to project an image content onto a projection surface in a region defining a display area; receiving captured images captured by at least one optical sensor of the projected image content on the projection surface; detecting, in the captured images, user touches of a plurality of designated locations of the projected image content on the projection surface; determining a position of an interaction area based on the detected user touches; determining, based on the determined position of the interaction area, whether the display area and the interaction area coincide; in response to determining that the display area and the interaction area coincide, interpreting detected user input in images captured by the at least one optical sensor; and in response to determining that the display area and the interaction area fail to coincide, instructing a user to adjust at least one of the projector and the at least one optical sensor so that the interaction area and the display area coincide.