Detailed Description

The PFeverCamAnalytics class provides analytics functions to process FeverCam images (change detection and black body localization)

Temperature change detection using DetectContentChanges which is useful to avoid invalid temperature readings caused by background
Black body localization in color and/or thermal image

Definition at line 33 of file PFeverCamAnalytics.h.

#include <PFeverCamAnalytics.h>

Constructor & Destructor Documentation

◆ PFeverCamAnalytics() [1/2]

PFeverCamAnalytics::PFeverCamAnalytics	(	double	i_changeThreshold = `1.`,
		int32	i_histSize = `500`,
		double	i_learningRate = `-1.`
	)

Constructs and empty, invalid, FeverCam calibration.

i_changeThreshold is the minimum image difference to consider that a pixel doesn't belong to background
i_histSize is the maximum number of frames that affect the background
i_learningRate is the rate at which background changes (0 doesn't update, 1 updates immediately) negative values let the algorithm automatically adjust

◆ PFeverCamAnalytics() [2/2]

PFeverCamAnalytics::PFeverCamAnalytics ( const PFeverCamAnalytics & other )

Constructs a shared copy of other.

◆ ~PFeverCamAnalytics()

virtual PFeverCamAnalytics::~PFeverCamAnalytics ( )

virtual

Destroys this object.

Member Function Documentation

◆ DetectContentChanges()

PResult PFeverCamAnalytics::DetectContentChanges	(	const PImage &	i_thermalImg,
		PImage &	o_contentChangesImg,
		int32 &	o_nbChangedPixels
	)

Detects content changes in input thermal image Outputs:

o_contentChangesImg: a E_GREY8U PImage with values 0 where no significant changes was detected, 255 for any pixel considered changed
o_nbChangedPixels: amount of pixels in input image that have been considered as significantly changes Fails if image is empty or input image size has changed since last call

◆ FindBlackBodyCandidates() [1/2]

static PResult PFeverCamAnalytics::FindBlackBodyCandidates	(	const PImage &	i_img,
		PList &	o_candidatesRects,
		bool	i_bFromThermalImage = `true`,
		int32	i_minArea = `40`,
		double	i_minAreaRatio = `0.8`
	)

static

Finds any area that might be a black-body in the input image Detection is done from expected appearance of black body:

black/dark in color images
bright with constant temperature in thermal images
rectangular

Parameters:

i_img: input PImage in which black body should be found
o_candidatesRects: List of PRectanglef objects, each one corresponding to a possible black body location
i_bFromThermalImage: indicates whether input image is thermal or color image
i_minArea: minimum area black body should have in image. Minimum size depends on image resolution and distance to black-body
i_minAreaRatio: minimum ratio between black body surface and candidate bounding box. Let's user adapt to rotated/non-parallel black body

Fails if:

Input image is empty
Minimum area is negative
Minimum area ratio is negative or larger than 1

◆ FindBlackBodyCandidates() [2/2]

static PResult PFeverCamAnalytics::FindBlackBodyCandidates	(	const PImage &	i_colorImg,
		const PImage &	i_thermalImg,
		const PFeverCamCalibration &	i_calib,
		PList &	o_candidatesRects,
		int32	i_minAreaColor = `40`,
		int32	i_minAreaTherm = `40`,
		double	minAreaRatio = `0.8`
	)

static

Finds black-body candidates in color and thermal images and outputs only those that match according to calibration Detection is done from expected appearance of black body:

black/dark in color images
bright with constant temperature in thermal images
rectangular Additionally, black-body must be detected in both color and thermal image to be returned

Parameters:

i_colorImg: input PImage from color camera in which black body should be found
i_thermImg: input PImage from thermal camera in which black body should be found
i_calib: input calibration (must be valid) to be used to filter candidates that don't match
o_candidatesRects: List of PRectanglef objects, each one corresponding to a possible black body location in thermal image coordinates
i_minAreaColor: minimum area black body should have in color image
i_minAreaTherm: minimum area black body should have in thermal image
i_minAreaRatio: minimum ratio between black body surface and candidate bounding box. Let's user adapt to rotated/non-parallel black body

Fails if:

One of the input images is empty
Calibration is invalid
Minimum area is negative
Minimum area ratio is negative or larger than 1

◆ SetLearningRate()

PResult PFeverCamAnalytics::SetLearningRate ( double i_learningRate )

Changes learning rate to adapt to a sudden change of background for example or to stop background learning.

Negative values mean algorithm adapts automatically
0 means algorithm doesn't update background
1 means background will be immediately updated. Note that while learning rate is at 1 no content change can be detected Fails if i_learningRate is larger than 1

Friends And Related Function Documentation

◆ PFeverCamAnalyticsImpl

friend class PFeverCamAnalyticsImpl

friend

Definition at line 130 of file PFeverCamAnalytics.h.