Overview

The Dwell Counter node keeps track of the number and how long each detected, tracked object has been present in the specified region in the video, can highlight objects, and adds the presence metadata to the frame metadata. This node makes it easy to build common use cases such as Overtime parking enforcement, Loitering alerts, etc.

This node has been deprecated in favor of Occupancy Monitor

This node requires a AI Model Node and a Track Objects Node before it in order to function properly.

Inputs & Outputs

Inputs : 1, Media Format : Raw Video
Outputs : 1, Media Format: Raw Video
Output Metadata : Presence Information

Properties

Property	Value
`objects_to_track`	Comma separated list of Detected Object labels to track, as specified in Model Labels ex. `car, person` Accepted formats: `object_label`: any object of this type, with or without a classifier attribute. Example: `car` `object_label.class_type`: any object of this type that has a specific classifier attribute. Example: `car.red` `object_label.`: any object of this type that has at least one classifier attribute. Example: `car.` (this will match `car.red`, `car.yellow`, etc)
`presence_threshold`	Number of seconds the object must be present to flag them on the video stream Ex. `60`
`display_roi`	Boolean. If true, ROI info will be drawn on video Ex. `true` / `false`
`display_objects`	Boolean. If true, Object info (presence duration, as well as highlight when it crosses presence threshold) will be drawn on video Ex. `true` / `false`
`rois`	Semicolon separated list of areas in the video within which the Presence Detector tracks these objects. If none is specified, the Presence Detector tracks objects within the entire frame. Format: `left1,top1,right1,bottom1; left2,top2,right2,bottom2` Ex: `10,10,100,100; 200,200,300,300`
`roi_labels`	Comma separated list of labels for each ROI in the `rois` list above. Format: `label1, label2` Ex: `door, window`
`persistent_storage`	Boolean. If true, the following analytics will be stored in disk and restored when the pipeline restarts: [roi_label]['total_objects'] Ex. `true` / `false`

Metadata

Metadata Property	Description
`nodes.<node_id>`	Describes the ROIs monitored by this node, and their properties. Format : as defined in the table below. `<node_id>` for Dwell Counter Nodes is of the form `annotate_presenceX` (ex. `annotate_presence1`)

Example

"nodes": {
    "annotate_presence1": {
        "type": "annotate_presence",
        "rois": {
            "<roi_label>": {
                "coords": [[<point1_x>, <point1_y>], 
                           [<point2_x>, <point2_y>], 
                           [<point3_x>, <point3_y>]],
                "total_objects": <int>,
                "objects_entered_delta": <int>,
                "objects_exited_delta": <int>,
                "objects_above_max_time_threshold_count": <int>,
                "objects_above_max_time_threshold_delta": <int>,
                "current_objects_count": <int>,
                "current_objects": {
                    "<object_tracking_id>": {
                        "first_seen": <seconds in ROI>,
                        "time_present": <seconds in ROI>
                    }
                }
            }
        }
    }
}

Format

Key	Type	Description
`<roi_label>`	Array of dictionaries	Contains information about this specific ROI
`<roi_label>.coords`	Dictionary	Contains the bounding box coordinates that represent this ROI
`<roi_label>.total_objects`	Integer	Number of objects seen in this ROI since the start of the pipeline
`<roi_label>.objects_entered_delta`	Integer	Number of objects that entered the ROI between last frame and this frame
`<roi_label>.objects_exited_delta`	Integer	Number of objects that left the ROI between last frame and this frame
`<roi_label>.objects_above_max_time_threshold_count`	Integer	Number of objects inside the ROI above the specified temporal threshold
`<roi_label>.objects_above_max_time_threshold_delta`	Integer	Number of new objects that exceeded the threshold between the last frame and this frame
`<roi_label>.current_objects_count`	Integer	Number of objects inside the ROI currently
`<roi_label>.current_objects`	Array of dictionaries	Information about the objects currently in the ROI `object_tracking_id` : Unique identifier for a specific object, as specified by `object.id` property (see Model Inference Node ) `first_seen` : Time in seconds when the object was first seen in the ROI `time_present` : Time in seconds that the object has been present in the ROI