Motion detection is the feature that watches for changes in a series of video images. The definition of what constitutes motion in a video can be based on highly sophisticated criteria.
- Software motion detection
- Motion detection is executed by the Archiver on the video stream set for recording, and motion events are generated by Security Center.
- Hardware motion detection
- Motion detection is executed by the video unit, and motion events are generated by the unit and sent to Security Center.
|Configuring motion detection settings||Config Tool||Unit's proprietary configuration tool1|
|Motion search task in Security Desk2||Yes||Limited support3|
|Shows motion indicators (green bars) in the timeline||Yes||See our Supported Device List4|
|Multiple motion detection zones||Yes||Camera-specific5|
|Requires additional server resources||Yes||No|
|Auto calibration of sensitivity6||Yes||No|
- To ease configuration of hardware motion detection, motion blocks derived from software motion detection are shown in Config Tool.
- The Motion search task does not support cameras using H.265 (HEVC) streams.
- Only Axis cameras with legacy motion detection are supported.
- For cameras with hardware motion detection, the green bars only indicate the presence of motion in the timeline (0% or 100%). For Axis cameras with legacy motion detection, the green bars also indicate the amount of motion as a percentage.
- Not all units support multiple motion detection zones. If you switch motion detection from Archiver to Unit, existing zone configurations not supported by the unit are lost.
- The unit and Archiver might interpret sensitivity differently, so testing your motion zones in Config Tool might not accurately reflect the unit's behavior.
To configure motion detection, you must specify areas of the video image, motion sensitivity, and a schedule for when to apply motion detection settings. Every camera has a default motion detection configuration based on the Always schedule. The default motion detection configuration can be modified but not deleted.
When an H.264 stream is selected as the recording stream, the Advanced settings button becomes available. Clicking this button opens the H.264 advanced motion detection settings dialog box which you can use to refine the motion detection settings.
A motion block is when motion is detected inside one of the blocks you configure on the video image. There is positive motion in a video image when the area covered by the block detects motion in two consecutive video frames. The number of motion blocks detected represents the amount of motion. A motion block is represented by a semi-transparent green square overlay on the video image.
Positive motion detection
Seeing motion blocks on the video does not necessarily mean that the system will generate a motion related event. It might be noise. To determine when motion started (Motion on event) and stopped (Motion off event), adjust the Sensitivity, Consecutive frame hits, Motion on threshold, and the Motion off threshold parameters to achieve the best results in the specific environment.
Best practices for configuring motion detection
- It is preferable to have sensitive settings that might trigger false motion events, than missing expected recordings when settings are not sensitive enough.
- All motion settings are stored in the Directory database, so make sure to back up your database when changes are made.
- Motion detection is the most basic video analytic capability. Due to possible false motion events, it should not be used to trigger alarms in critical situations, for example in replacement to a specialized intrusion detection system.
- If you set the Time to record before an event parameter to a high value, it increases the memory (RAM) resources required by the Archiver. This reduces the camera count allowed on the Archiver. Cameras with a higher resolution have the same effect on the memory resources.
- It is always possible to use MJPEG streams.
- It is possible to use MPEG-4 streams.
- It is also possible to use H.264 streams, but because of the notion of profiles, some cameras must be configured through the additional H.264 advanced motion detection settings dialog box.