Scene Analysis

Scene Analysis detects objects or events in a scene that are deemed important to the user. These events might be a vehicle breaching a red light, the presence of an abandoned bag, or traffic congestion.

Configuration Parameter Description
BackgroundUpdateOnAlarm Specifies whether to update the background in areas that are generating alarms.
Input The image track to analyze.
MaskOverlay Specifies whether to attempt to mask areas of the view that remain static.
MaxInputQueueLength Can be used to place a limit on latency.
NumParallel The maximum number of CPU threads to use for scene analysis.
SampleInterval The interval at which frames are selected to be analyzed.
Type The analysis engine to use. Set this parameter to SceneAnalysis.
TimeBetweenAlarms The minimum interval between alarms.
TrainingCfg The path to the training configuration file to use to identify suspicious events.
TrainingCfgName The name of the training configuration file to use to identify suspicious events.

Output Tracks

The following table describes the tracks that are generated by this engine. The Output column indicates whether the information contained in the track is included by default in the output created by an output task (when you don't set the Input parameter for the output task).

Output track Type Description Output
Data SceneAnalysisResult Contains one record, describing the analysis results, for each alarm object in each video frame. If an object causes an alarm in more than one category there are separate records for each category. No
DataWithSource SceneAnalysisResultAndImage

The same as the Data track, but each record also includes the source frame.

No
Result SceneAnalysisResult Contains a record for each detected alarm object. If an object causes an alarm in more than one category there are separate records for each category. Yes
ResultWithSource SceneAnalysisResultAndImage

The same as the Result track, but each record also includes the best source frame.

No
Start SceneAnalysisResult

The same as the Data track, except it contains only the first record of each event.

No
End SceneAnalysisResult

The same as the Data track, except it contains only the last record of each event.

No
TrafficLight   Media Server outputs a record when the traffic lights change. No
PTZChange   Media Server writes a record to this track when a PTZ camera is moved away from, or back to, the configured scene. The field "connected" contains the value false when the camera is moved away from the scene and Media Server stops generating alarms, and true when the camera is moved back to the scene and Media Server resumes generating alarms. No

SceneAnalysisResult

Field name Type Description
id UUIDData A universally unique identifier to identify the object
object SceneAnalysis_Object

Information about the alarm object. This includes information such as:

  • The size of the alarm object.
  • The bounding box that contains the alarm object.
  • The position of the center of the alarm object.
  • The velocity of the alarm object.
  • The amount of time that the object has been within the region of interest.

SceneAnalysisResultAndImage

The same as SceneAnalysisResult records, with the following additional fields.

Field name Type Description
image ImageData The source frame