This chapter does not appear in the book.
This chapter explains how to use a webcam to detect change or movement in a scene. Frames are grabbed from the camera and drawn rapidly onto a panel, using the code developed in the previous chapter. A movement detector analyzes consecutive frames and highlights any change/movement with a pair of crosshairs at the center-of-gravity of the motion. The application, called MotionDetector, is shown in the picture at the top of this page.
The crosshair coordinates will be employed in the next chapter to guide a DreamCheeky Missile Launcher to a target.
The detection algorithm is implemented using the OpenCV computer vision library. OpenCV is such an important tool that I'll spend a little time explaining its capabilities, and especially its Java interface (called JavaCV), before describing the detection application.