Documentation for Axxon Next 4.2.2. Documentation for other versions of Axxon Next is available too.
To configure a VMD:
- 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, see 4-5).
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 your convenience with setting sensitivity value, in the preview window you can see the Motion Mask. To disable it, select No in the Motion Mask (2) field.
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.
To get tracked objects and their parameters (percentage of the FoV width/height, color) displayed in the Preview window, select Yes in the Object Tracking field (3).
The Video Motion Detection tool can receive tracking metadata generated by the Motion Mask. The metadata are recorded into the database by default. To disable, select No in the RecordObject Tracking (1).
Though the VMD metadata are essentially less accurate than those from the Object Tracker (see Object Tracker), you win on lower CPU usage.
You have to update the license file to use this feature. To do this, contact your AxxonSoft manager..
VMD configuration is now complete.