This demo is an example of using the Image Acqisition Toolbox from within Simulink. The Image Acquisition Toolbox is called via a MATLAB Function block to return a frame of data. The Signal Processing Blockset is used to analyze the data and determine if there is motion in the frame. If there is motion, the quadrant that the motion was detected in is highlighted.
In order for the detection to work properly, it will likely be necessary to tune the threshold value to suit your particular scene conditions.