A Camera Based Virtual Keyboard with Touch Detection by Shadow Analysis

Recent years have marked a sharp increase in the number of ways in which people interact with computers. Where the keyboard and mouse were once the primary interfaces for controlling a computer, users now utilize touchscreens, infrared cameras (like Microsoft’s Kinect), and accelerometers (for example, within the iPhone) to interact with their technology. In light of these changes and the proliferation of small cameras in many phones and tablets, humancomputer interface researchers have investigated the possibility of implementing a keyboard-style interface using a camera as a substitute for actual keyboard hardware. Broadly speaking, these researchers envision the following scenario: A camera observes the user’s hands, which rest on a flat surface. The camera may observe the hands from above the surface, or at an angle. The virtual keyboard’s software analyzes those images in real-time to determine the sequence of keystrokes chosen by the user. These researchers envision several applications for this technology: