: Contactless Human-Machine-Interfaces (HMIs) are an important issue in various applications where a haptic interaction with an input device is not possible or not appropriate. Newly developed Time-of-Flight cameras provide 3D information of the observed scene in real-time at constant lateral resolutions of thousands of pixels. Additionally, a gray-value image of the observed scene is available. Our work compromises three major contributions: First, the robust and real-time capable segmentation of the hand by incorporating 3D and gray-value information; Second, the reliable classification of the performed static gesture using robust features; Third, the design of an HMI which uses the classified gesture as well as the 3D position of the hand to enable complex and convenient user interactions. The benefit of using a ToF camera is that the 3D information is just not available from classical 2D camera systems and thus only with ToF cameras the three dimensions of freedom which are give...