In an exemplary method for obtaining a contour image of a tooth, which can be executed at least in part by a computer, movement of an intra-oral camera can be detected by acquiring a first video image frame that includes the tooth and processing the first video image frame to detect one or more edges of the tooth in the first video image frame and acquiring a second video image frame that includes the tooth and processing the second video image frame to detect the one or more edges of the tooth in the second video image frame. The method can compare corresponding edge locations between the first and second processed video image frames and projects a fringe pattern illumination onto the tooth from the camera, capturing and storing one or more still images of the fringe pattern according to the detected camera movement.
