Image checks
Raise an alarm when a camera's lens is covered, its view is moved, or its image loses focus, with a sensitivity and an optional schedule.
Contents
Image checks raise an alarm when a camera's picture is tampered with or degrades: the lens is covered, the camera is moved, or the image loses focus. They are an add-on, enabled per camera, with Verify, Verify + VMS, and Kalytera Monitoring. You set them up once and then only get alarms; there are no reference pictures to manage.
Turn image checks on
- Open the camera under Cameras, stay on its Overview, and select Edit details.
- Turn on Image checks.
- Choose the Sensitivity, the faults to report, and when to Check, as described below.
- Select Save details.
The checks learn the camera's normal view by themselves, including its day, night, and infrared views. While they learn, the camera's overview says so.
Sensitivity
| Sensitivity | Reacts to |
|---|---|
| Low | Only large problems that last about two minutes. |
| Normal | Clear problems that last about half a minute. This is the default. |
| High | Smaller problems after about 15 seconds. |
Choose what raises an alarm
Under Raise an alarm when, tick the faults to report:
- The lens is covered, or the image goes dark or washed out
- The camera is moved or its view changes (leave off for PTZ cameras)
- The image loses focus
For a scene that is left unlit at night, tick Don't raise an alarm when the image is only dark. A lens covered so that the image goes black is then not reported either; covers that let light through still are.
Check on a schedule
Check is Always by default. Choose one of your schedules to check the camera only during its periods; outside them, the camera is not checked. Schedules are managed under Cameras > Schedules; see Recording, retention, and evidence.
Status on the camera's overview
The Image checks card on the camera's Overview shows one status line:
- On, with a detail such as No problem found., Learning the camera's view., or Paused outside its schedule.
- Problem found, with what was found and since when.
- Off, or Not active when the add-on is no longer active for the camera.
Image alarms
A confirmed fault raises one alarm per episode, named Image problem, without any rule. It carries the normal snapshot and clip from the camera's recording. Image alarms are handled like any other alarm (see Alarms and incidents), and they are not sent to monitoring stations.
After you move a camera on purpose, resolve its "Camera moved" alarm while it shows the new view: the new view becomes the normal one.