Video motion detection (VMD) recognizes a change in the video signal in relation to a reference image of static background (a specific location , video scene or part of a video scene). For VMD, a block of 80x60 pixels is sampled from the raw image. If the brightness levels of same pixels in the current frame and the background / reference image change and exceed the threshold valiue defined by the Sensitivity: Contrast (7 if sensitivity is at  16 and 29 at the sensitivity threshold value of 0). Motion is detected  if the number of brighter / darker pixels  exceeds the threshold value defined Sensitivity: Size (3 pixelsfor a 80x60 image with sensitivity values of 10 and 53 pixels at the sensitivity value of 0).

You can create VMD zones or VMD privacy masks  in the viewing tile / FoV in the same way as with situation analysis detection tools (see steps 2-4 in Section Setting Common Detection Zones).