Overview

The Speed Estimation node estimates speeds of objects in a ROI and sets triggers based on low/high thresholds. This node makes it easy to build common use cases such as No running zones, traffic jams, etc.

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 : Speed Information

Properties

Property	Value
`rois`	Semicolon separated list of areas in the video within which the Proximity Detector tracks these objects. If none is specified, the Proximity 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`
`object_types`	Comma separated list of object types to measure speed. 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)
`miles_per_pixel`	Approximate number of miles per pixel. Obtain by dividing image width by the number of miles between left and right ends of the view. Ex. 0.0004
`speed_trigger_threshold_high_mph`	Set a trigger when speed exceeds the high threshold.. Ex. `20`
`speed_trigger_threshold_low_mph`	Set a trigger when speed is below the low threshold. Ex. 2
`display_objects_mode`	Display objects that meet this criteria on the video Options: `none` : None `triggered` : Only those above or below the thresholds. * `all` : All
`display_roi`	If true, ROI will be drawn on video

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 Speed Estimation Nodes is of the form `annotate_speedX` (ex. `annotate_speed1`)

Example

"nodes": {
    "annotate_speed1": {
        "type": "annotate_speed",
        "rois": {
            "<roi_label>": {
                "coords": [[<point1_x>, <point1_y>], 
                           [<point2_x>, <point2_y>], 
                           [<point3_x>, <point3_y>]],
                "average_speed": <int>,
                "objects_low_speed_count": <int>,
                "objects_low_speed_delta": <int>,
                "objects_medium_speed_count": <int>,
                "objects_medium_speed_delta": <int>,
                "objects_high_speed_count": <int>,
                "objects_high_speed_delta": <int>,                 
                "objects_low_speed": [object_id1, object_id2...],
                "objects_medium_speed": [object_id1, object_id2...],
                "objects_high_speed": [object_id1, object_id2...]
            }
        }
    }
}

Format

Key	Type	Description
`<roi_label>`	Array of dictionaries	Contains information about this specific ROI
`<roi_label>.coords`	Array of Arrays	Contains the bounding box coordinates that represent this ROI
`<roi_label>.objects_low_speed_count`	Integer	Number of objects currently in this ROI below the`speed_trigger_threshold_low_mph`
`<roi_label>.objects_low_speed_delta`	Integer	Number of new objects in the ROI whose speed was below `speed_trigger_threshold_low_mph` between last frame and this frame
`<roi_label>.objects_medium_speed_count`	Integer	Number of objects currently in this ROI between the`speed_trigger_threshold_low_mph` and `speed_trigger_threshold_high_mph`
`<roi_label>.objects_medium_speed_delta`	Integer	Number of new objects in the ROI whose speed was between `speed_trigger_threshold_low_mph` and `speed_trigger_threshold_high_mph` between last frame and this frame
`<roi_label>.objects_high_speed_count`	Integer	Number of objects currently in this ROI above the`speed_trigger_threshold_high_mph`
`<roi_label>.objects_high_speed_delta`	Integer	Number of new objects in the ROI whose speed was above `speed_trigger_threshold_high_mph` between last frame and this frame
`<roi_label>.objects_low_speed`	List of long integers	List of object IDs of low speed objects
`<roi_label>.objects_medium_speed`	List of long integers	List of object IDs of medium speed objects
`<roi_label>.objects_high_speed`	List of long integers	List of object IDs of high speed objects