ds::SlidingWindowAggregator Class Reference

DeepSight SDK sliding time window aggregator class. More...

Public Member Functions
	SlidingWindowAggregator (std::chrono::milliseconds maxWindowDuration=std::chrono::milliseconds{ 10000 })
	ds::SlidingWindowAggregator constructor. More...
	~SlidingWindowAggregator () noexcept
	ds::SlidingWindowAggregator destructor.
	SlidingWindowAggregator (SlidingWindowAggregator &&slidingWindowAggregator) noexcept
	ds::SlidingWindowAggregator move constructor.
SlidingWindowAggregator &	operator= (SlidingWindowAggregator &&slidingWindowAggregator) noexcept
	ds::SlidingWindowAggregator move assignment operator.
void	newDetections (const std::vector< ds::Person > &people)
	Adds new detections to the current state of aggregations. More...
std::vector< ds::AggregatedPerson >	getAggregations (std::chrono::milliseconds windowDuration=std::chrono::milliseconds{ 0 })
	Get people aggregations in the provided time window. More...
std::chrono::milliseconds	getMaxWindowDuration () const noexcept
	Returns the maximum window duration data will be internaly stored. More...
void	setMaxWindowDuration (std::chrono::milliseconds maxWindowDuration) noexcept
	Sets the maximum window duration data will be internaly stored. More...
void	clean () noexcept
	Discards all detections from the internal state. More...

Detailed Description

DeepSight SDK sliding time window aggregator class.

The ds::SlidingWindowAggregator class aggregates all information retrieved for each unique person during a window of time. It is therefore possible to know what happened in the last time window (eg. in the last 10 seconds) at any given time, without having to preemptively initialize a ds::Aggregator. All detections provided to ds::SlidingWindowAggregator::newDetections calls outside of the window will be discarded.

In order to implement a sliding window aggregation strategy, all the detections within the time window need to be stored internally. Therefore the larger the time window, the larger the memory requirements.

Constructor & Destructor Documentation

SlidingWindowAggregator()

ds::SlidingWindowAggregator::SlidingWindowAggregator

(

std::chrono::milliseconds

maxWindowDuration = std::chrono::milliseconds{ 10000 }

)

ds::SlidingWindowAggregator constructor.

Parameters

maxWindowDuration

The maximum window of time over which the aggregation will be performed.

The maximum time window is defined as the time between (std::chrono::system_clock::now() - maxWindowDuration) and (std::chrono::system_clock::now())

Member Function Documentation

clean()

void ds::SlidingWindowAggregator::clean ( )

noexcept

Discards all detections from the internal state.

getAggregations()

std::vector< ds::AggregatedPerson > ds::SlidingWindowAggregator::getAggregations

(

std::chrono::milliseconds

windowDuration = std::chrono::milliseconds{ 0 }

)

Get people aggregations in the provided time window.

Parameters

windowDuration

The window of time over which the aggregation will be performed.

Returns

A vector of aggregated people.

This function aggregates all people detected in the last windowDuration milliseconds. The windowDuration parameter cannot be larger than the maxWindowDuration provided during construction. All detections older than (std::chrono::system_clock::now() - maxWindowDuration) will be discarded. A person with a detection duration shorter that 1 second is considered a false positive and therefore not returned.

getMaxWindowDuration()

std::chrono::milliseconds ds::SlidingWindowAggregator::getMaxWindowDuration ( ) const

noexcept

Returns the maximum window duration data will be internaly stored.

Returns

The maximum window duration in milliseconds.

newDetections()

void ds::SlidingWindowAggregator::newDetections

(

const std::vector< ds::Person > &

people

)

Adds new detections to the current state of aggregations.

Parameters

people

New detections to aggregate.

This function stores the new detections in the internal buffer. All detections outside the time window will be discarded.

Example usage:

ds::SlidingWindowAggregator windowAggregator( std::chrono::milliseconds{ 5000 } );
 
while( true )
{
  cap >> frame;
  if( frame.empty() )
    break;
 
  // Analyze frame
  std::vector<ds::Person> people = ds.analyze( frame );
 
  // Add new detections to the aggregation window
  windowAggregator.newDetections( people );
}
 
// Count how many unique people were detected during the last 5 seconds of the video
std::cout << windowAggregator.getAggregations().size() << std::endl;

setMaxWindowDuration()

void ds::SlidingWindowAggregator::setMaxWindowDuration ( std::chrono::milliseconds  maxWindowDuration )

noexcept

Sets the maximum window duration data will be internaly stored.

Parameters

maxWindowDuration

The maximum window duration in milliseconds.