Structured Light Illumination Methods for Continuous Motion Hand and Face-computer Interaction
Jeffrey R. Charles, Gavit Laurence, L. Daniel · InTech eBooks · 2008
Human to computer interfaces have been so far dominated by hand held and/or physical interfaces such as keyboards, mice, joysticks, touch screens, light pens, etc.. There has been considerable study in the use of non-contact interface technology that use image motion, stereo vision, and time of flight ranging devices. Using image processing of a single camera image, there is difficulty segmenting the feature of interest and poor depth accuracy. Stereo vision requires two cameras and is dependent on distinct features on the surface/object being measured, and time of flight systems are very expensive and lack close range accuracy. We believe that Structured Light Illumination is a practical solution to the non-contact interface problem because of the simplicity of one camera and one projector, and its direct and accurate measurement of human hands and faces. Furthermore, with the advent of projected keyboards for augmented reality interfacing, a camera and projector are already present. In fact, the keyboard pattern could be used as the SLI pattern. In general, SLI, particularly the single pattern methods described in this research, are accurate, surface feature independent, and require only a simple slide projection in either visible or NearInfra-Red light frequencies. The illumination source only requires efficient LED based illumination technology. As discussed in the results section, the accuracy of the depth measurement is within 1 mm so the demonstration is not just a non-contact "mouse" but a five finger analog controller. Full finger motion control could be used for a wide range of