An effective real-time fingertip positioning system based on gradient information extraction from frame image sequences

This paper presents a writing-in-the-air fingertip positioning system using a camera as an input to a computer. The frame difference method is employed to extract the finger movement area and the vertical gradient is calculated in this area to extract the fingertip contour information. Then the fingertip is located by finger geometric properties. 1000-photos library is built to stimulate various operating environments and test the effectiveness of this system. The system achieves a speed of 100 frames per second (fps) with an accuracy rate of 97.0%.