This chapter does not appear in the book.
The webcam is a great 'building block' for creating novel forms of user input. At the lowest level, the camera repeatedly delivers images (e.g. of the user's hand or face) to a processing stage, which employs a range of image processing and computer vision techniques to extract information about the changing scene (e.g. hand gestures, face detection).
This chapter concentrates on how to generate webcam snaps using the JMF (Java Media Framework), and later chapters will apply various processing techniques to those pictures. The aim is to grab images as quickly as possible, and display them in rapid succession in a JPanel. The panel output includes the number of pictures displayed so far and the average time to take a snap, information that'll help me implement suitable processing rates in later stages. The picture at the top of this page shows the JMF application.
The information about the picture is written in blue in the bottom-left corner of the image; it says "Pic 2382 10.4 ms". The application always employs the video format with the largest frame size (normally 640 by 480 pixels), and the output shows that such a frame can be generates roughly every 10ms (on my slow test machine).