Summary

This completes a quick introduction to motion detection using Pure Data and the GEM library. We learned how to detect the presence of a subject in front of a static background. By comparing two consecutive frames, we identified movement in front of the webcam. Using the position given by the GEM library, we used graphical shape to follow the movement of a subject. By comparing the color information of a specific pixel, we could detect precise movement in a specific pixel in the video image. With this information, we could implement interactive hotspots that exist in virtual space. In the next chapter, we will enhance the graphical display by using particles system.