By default, VMD (video motion detection) covers the entire FoV. In the FoV, you can set privacy masks - closed areas, inside of which you want no detection.
Privacy masks are created similar to scene analysis configuration (see Setting General Zones for Scene Analytics).
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, pixel brightness is averaged with Median Filtering to get a block of 80x60 cells from the raw image. If the brightness levels of same cells in the current frame and the background / reference image change and exceed the threshold value defined by the Sensitivity: Contrast (for example, 7 if the sensitivity threshold value is at 16 and 29 if sensitivity is 0). Motion is detected if the number of brighter / darker pixels exceeds the threshold value defined Sensitivity: Size (for example, 3 cells from the 80x60 block at a sensitivity value of 10 and 53 at 0).
For you convenience with VMD configuration, in the preview window, you can see the motion mask.
If there is motion, but it does not exceed the threshold value (because of the detection sensitivity), the mask cells are colored green. If motion triggers VMD, the cells turn red.