This chapter has presented two abilities to make your robot more interactive. To talk to your robot and have it speak to you makes it become alive with personal characteristics. The more voice commands or phrases it responds to and the more phrases your robot can speak, the more personality it will have.

An additional customization would be to interact with your robot face-to-face. Having your robot turn when spoken to and having him find the face of the speaker will add an air of awareness. The capability to detect a face would be an advantage.

There are two primary methods available in ROS to detect faces from a camera image stream. The first method is using a cascade classifier with Haar or LBP-like features. This relies on a method provided by OpenCV. The second method uses Eigenfaces to recognize faces in an image. Descriptions of these two methods are provided in the next two sections. The best approach to test these methods is to begin by using a...