DwellTimeTracking

Detects object dwell time in a pre-defined zone.

This module provides a pipeline element to track dwell time of any bounding box for a period of time. This module can also check for zone intersection, and only track dwell times for bounding boxes that have intersected with a zone.

Examples:

REST API:

WIP

Configuration File:

short-from : dwell-time-tracking:<i-max_age>:<i-min_hits>:<i-history_buffer>:<s-region_to_check>:<f-ratio>: <i-ma_len>:<i-dwell_time>:<s-inside_zones

pipeline:
- person-detection-nano:a:0.3:0.3
- dwell-time-tracking:3:3:50:bottom:0.2:3:15
sources:
- address: videos/loiter_sample.mp4
- type: file

DwellTimeTracking Objects

class DwellTimeTracking(Element)

Detects object dwell time in a pre-defined zone.

Attributes:

• name str - The name of the element.
• max_age int - the number of consecutive iterations for which the tracker needs to be maintained for any object after it has stopped being detected.
• min_hits int - the min length of tracking history (in number of points) for which intersection with a defined zone is checked.
• history_buffer int - the length of the list containing history as a cyclic buffer
• region_to_check str - the region of the bounding box that should overlap for the zone intersection to be registered.
• ratio float - the ratio of the bbox to be considered in the marked perspective for the zone intersection to be detected.
• ma_len int - the average change in a data series over time.
• dwell_time int - time in seconds for dwell time to be marked as exceeded.
• inside_zones str - flag to check for dwell time within a zone.

Examples:

ele = DwellTimeTracking("3", "3", "50", "bottom", "0.2", "3", "15")

extract_params

@staticmethod
def extract_params(model_params)

Extract the parameters for this element.

Arguments:

• model_params List[str] - The parameters for this element.

Returns:

• max_age int - the number of consecutive iterations for which the tracker needs to be maintained for any object after it has stopped being detected.
• min_hits int - the min length of tracking history (in number of points) for which intersection with defined zone is checked.
• history_buffer int - the lenght of the list containing history as a cyclic buffer
• region_to_check str - the region of the bounding box that should overlap for the zone intersection to be registered.
• ratio float - the ratio of the bbox to be considered in the marked perspective for zone intersection to be detected.
• ma_len int - the average change in a data series over time.
• dwell_time int - time in seconds for dwell time to be marked as exceeded.
• inside_zones str - flag to check for dwell time within a zone.

Raises:

• ExtractParameterException - If the parameters are not valid.

Examples:

params = DwellTimeTracking.extract_params(["3", "3", "50", "bottom", "0.2", "3", "15"])
ele = DwellTimeTracking(*params)

process

def process(meta)

Process the bounding boxes.

This is the main function for this element. It takes the bounding boxes and checks for bounding boxes exceeding a preset dwell_time, it also checks for zone intersection to flag only bounding boxes that are inside a zone and also found to exceed the dwell time.

Arguments:

• meta dict - The metadata to process.

Returns:

• meta dict - The processed metadata.

Examples:

ele = DwellTimeTracking("3", "3", "50", "bottom", "0.2", "3", "15")
meta = ele.process(meta)