A java based programming environment - processing - free from processing.org.
here it uses a free library - openCV - to detect blobs in a live video capture - some parts like - hands or head or the entire human are evidenced through some visual effects.
A java application - processing which can be downloaded free from processing.org
Here it uses a free library - openCV - made by intel. .. to convert all the pixels in an image - in fact in a movie - a capture from the webcam. If the color of a pixel is "higher" comparing to a threshold it turns black - otherwise it becomes white.