Abstract: A method for determining gestures in the beam region of a projector includes: projecting an image onto a surface with the aid of the projector, using light; measuring a first set of light intensities of light backscattered from the direction of the surface, under the influence of a gesture made in the beam region of the projector; assigning the measured light intensities to, in each instance, a position of the image projected by the projector; at a first time point, generating a first light intensity function over a second set of positions, which are assigned measured light intensities; at a second time point, generating at least one second light intensity function over the second set of positions; and determining the gesture made, based on the result of a comparison between the first and second light intensity functions.