SG126697A1 - Methods and devices for inputting data to a computer system - Google Patents

Abstract

A user employs a pointing device 3 having an axis to point at a display 2 which displays an image controlled by a computer. The pointing device 3 may be a simple stick, or even a user's finger or arm. Images of the pointing device 3 are taken by two cameras 5, 7. Each of these images is a line in the two dimensional image plane of the corresponding camera. The line in one of the image planes is transformed to give a line in the other of the image planes, and the point of intersection of the two lines is found, corresponding to the position in that common co-ordinate frame of the point of intersection of the axis of the pointing device 3 with the display 2. The co-ordinates of the point of intersection of the lines are transformed by a predetermined co-ordinate transformation into the plane of the display, and into another co-ordinate frame corresponding to a monitor of the computer. Software in the computer then varies the image displayed on the display and/or uses the data to trigger other operations on the PC.