A method and apparatus for identifying user gestures to control an interactive display identifies gestures based on a bounding box enclosing points at which a user contacts a touch sensor corresponding with the display surface and permits use of inexpensive and highly reliable grid-based touch sensors that provide a bounding box to describe contact information. In identifying gestures, position, motion, shape, and deformation of the bounding box may be considered. Center, width, height, aspect ratio, length and orientation of the bounding box diagonal may be determined. A stretch factor, defined as the maximum of the ratio of the height of the bounding box to the width of the bounding box and the ratio of the width of the bounding box to the height of the bounding box, may also be computed. Gestures may be identified based on the changes in time of these characteristics and quantities.