Search by tampering type is used to search based on video image analysis and identify the pattern of changes. For correct operation of the search by tampering type, the following is required:

• Access permissions to search in the archive (see Role).
• The video clarity detector must be configured and connected to the camera (see Video clarity detector).

To search by tampering type:

1. Open the required layout (see Configuring layouts).
2. Select the required camera.
3. Click the Search button in the lower right corner of the surveillance window (see Search in archive).
4. Set a search interval (see Setting a search interval, Search in archive).
5. Click the button.
6. Select Search by tampering type.
7. Specify the search criteria listed in the table:
   

   Criterion	Value	Description
   Search by tampering type
   Tampering type		Select the tampering type from the drop-down list
   	Select all	By default, the checkbox is clear. If you want to select all tampering types, set the checkbox
   	Blurred image	By default, the checkbox is clear. Events that occurred when the edges of a video image were blurred are displayed. For example, an event that occurred when a video image was blurry due to a dirty lens. If this type of search isn’t required, clear the checkbox
   	Compression artifacts	By default, the checkbox is clear. If you want to find an event that occured when compression artifacts appeared on the video image, set the checkbox
   	Image noise	By default, the checkbox is clear. If you want to find an event that occurred when noise appeared on the video image, set the checkbox. For example, an event that occurred when the bitrate was low or when there were ripples in the image (snow)
   	Quality degradation	By default, the checkbox is clear. If you want to find an event that occurred when video quality degraded, set the checkbox. For example, an event that occured when the lens flared, the focus was out, the camera lens was blocked, or the video image illumination dropped sharply
   	Scene change	By default, the checkbox is clear. If you want to find an event that occurred when the video background changed, which indicated a change in the camera position, set the checkbox

   
   
8. Click the Search button.

The search results panel displays the frames that meet the specified search criteria: