Subsets are used to store temporary collections of pixels for comparison between the reference and deformed images. The data that is stored by a subset is a list of x and y corrdinates of each pixel (this allows for arbitrary shape) and containers for pixel intensity values. More...

#include <DICe_Subset.h>

Public Member Functions
	Subset (int_t cx, int_t cy, Teuchos::ArrayRCP< int_t > x, Teuchos::ArrayRCP< int_t > y)

	Subset (const int_t cx, const int_t cy, const int_t width, const int_t height)

	Subset (const int_t cx, const int_t cy, const Conformal_Area_Def &subset_def)

virtual	~Subset ()
	virtual destructor

int_t	num_pixels () const
	returns the number of pixels in the subset

int_t	centroid_x () const
	returns the centroid x pixel location

int_t	centroid_y () const
	returns the centroid y pixel location

void	update_centroid (const int_t cx, const int_t cy)
	update the centroid of a subset

const int_t &	x (const int_t pixel_index) const

const int_t &	y (const int_t pixel_index) const

const scalar_t &	grad_x (const int_t pixel_index) const

const scalar_t &	grad_y (const int_t pixel_index) const

bool	has_gradients () const
	returns true if the gradients have been computed

Teuchos::ArrayRCP< scalar_t >	grad_x_array () const
	returns a copy of the gradient x values as an array

Teuchos::ArrayRCP< scalar_t >	grad_y_array () const
	returns a copy of the gradient x values as an array

intensity_t &	ref_intensities (const int_t pixel_index)

intensity_t &	def_intensities (const int_t pixel_index)

void	initialize (Teuchos::RCP< Image > image, const Subset_View_Target target=REF_INTENSITIES, Teuchos::RCP< Local_Shape_Function > shape_function=Teuchos::null, const Interpolation_Method interp=KEYS_FOURTH)

void	write_tiff (const std::string &file_name, const bool use_def_intensities=false)

void	write_subset_on_image (const std::string &file_name, Teuchos::RCP< Image > image, Teuchos::RCP< Local_Shape_Function > shape_function=Teuchos::null)

intensity_t	max (const Subset_View_Target target=REF_INTENSITIES)

intensity_t	min (const Subset_View_Target target=REF_INTENSITIES)

scalar_t	mean (const Subset_View_Target target)

scalar_t	mean (const Subset_View_Target target, scalar_t &sum)

void	round (const Subset_View_Target target)
	round the values in the subset to the nearest integer number

scalar_t	gamma ()
	returns the ZNSSD gamma correlation value between the reference and deformed subsets

scalar_t	diff_ref_def () const
	returns the un-normalized difference between the the reference and deformed intensity values

scalar_t	sssig ()
	returns the SSSIG value for the reference intensities

void	reset_is_active ()
	reset the is_active bool for each pixel to true;

bool &	is_active (const int_t pixel_index)
	returns true if this pixel is active

int_t	num_active_pixels ()
	returns the number of active pixels in the subset

bool &	is_deactivated_this_step (const int_t pixel_index)
	returns true if this pixel is deactivated for this particular frame

void	reset_is_deactivated_this_step ()
	reset the is_deactivated_this_step bool for each pixel to false

bool	is_conformal () const
	True if the subset is not square and has geometry information in a Conformal_Area_Def.

const Conformal_Area_Def *	conformal_subset_def () const
	Returns a pointer to the subset's Conformal_Area_Def.

int_t	sub_image_id () const
	Return the id of the sub-region of a global image to use.

void	set_sub_image_id (const int_t id)
	set the sub_image_id

scalar_t	noise_std_dev (Teuchos::RCP< Image > image, Teuchos::RCP< Local_Shape_Function > shape_function)
	Returns an estimate of the noise standard deviation for this subset based on the method of J. Immerkaer, Fast Noise Variance Estimation, Computer Vision and Image Understanding, Vol. 64, No. 2, pp. 300-302, Sep. 1996 The estimate is computed for a rectangular window that encompases the entire subset if the subset is conformal. More...

scalar_t	contrast_std_dev ()
	Returns the std deviation of the image intensity values.

void	turn_off_obstructed_pixels (Teuchos::RCP< Local_Shape_Function > shape_function)
	EXPERIMENTAL Check the deformed position of the pixel to see if it falls inside an obstruction, if so, turn it off. More...

void	turn_on_previously_obstructed_pixels ()
	EXPERIMENTAL See if any pixels that were obstructed to begin with are now in view, if so use the newly visible intensity values to reconstruct the subset. More...

bool	is_obstructed_pixel (const scalar_t &coord_x, const scalar_t &coord_y) const
	EXPERIMENTAL Returns true if the given coordinates fall within an obstructed region for this subset. More...

std::set< std::pair< int_t, int_t > > *	pixels_blocked_by_other_subsets ()
	EXPERIMENTAL Returns a pointer to the set of pixels currently obstructed by another subset.

std::set< std::pair< int_t, int_t > >	deformed_shapes (Teuchos::RCP< Local_Shape_Function > shape_function=Teuchos::null, const int_t cx=0, const int_t cy=0, const scalar_t &skin_factor=1.0)
	EXPERIMENTAL Return the deformed geometry information for the subset boundary.

Private Attributes
int_t	num_pixels_
	number of pixels in the subset

Teuchos::ArrayRCP< intensity_t >	ref_intensities_
	pixel container

Teuchos::ArrayRCP< intensity_t >	def_intensities_
	pixel container

Teuchos::ArrayRCP< scalar_t >	grad_x_
	container for grad_x

Teuchos::ArrayRCP< scalar_t >	grad_y_
	container for grad_y

Teuchos::ArrayRCP< bool >	is_active_
	pixels can be deactivated by obstructions (persistent)

Teuchos::ArrayRCP< bool >	is_deactivated_this_step_
	pixels can be deactivated for this frame only

Teuchos::ArrayRCP< int_t >	x_
	initial x position of the pixels in the reference image

Teuchos::ArrayRCP< int_t >	y_
	initial x position of the pixels in the reference image

std::set< std::pair< int_t, int_t > >	obstructed_coords_
	EXPERIMENTAL Holds the obstruction coordinates if they exist. NOTE: The coordinates are switched for this (i.e. (Y,X)) so that the loops over y then x will be more efficient.

std::set< std::pair< int_t, int_t > >	pixels_blocked_by_other_subsets_
	EXPERIMENTAL Holds the pixels blocked by other subsets if they exist. NOTE: The coordinates are switched for this (i.e. (Y,X)) so that the loops over y then x will be more efficient.

int_t	cx_
	centroid location x

int_t	cy_
	centroid location y

bool	has_gradients_
	true if the gradient values are populated

Conformal_Area_Def	conformal_subset_def_
	Conformal_Area_Def that defines the subset geometry.

bool	is_conformal_
	The subset is not square.

int_t	sub_image_id_

Detailed Description

Subsets are used to store temporary collections of pixels for comparison between the reference and deformed images. The data that is stored by a subset is a list of x and y corrdinates of each pixel (this allows for arbitrary shape) and containers for pixel intensity values.

Constructor & Destructor Documentation

◆ Subset() [1/3]

DICe::Subset::Subset	(	int_t	cx,
		int_t	cy,
		Teuchos::ArrayRCP< int_t >	x,
		Teuchos::ArrayRCP< int_t >	y
	)

constructor that takes arrays of the pixel locations as input (note this type of subset has not been enabled for obstruction detection, only conformal subsets with defined shapes have this enabled. See the constructor below with a subset_def argument)

Parameters

cx	centroid x pixel location
cy	centroid y pixel location
x	array of x coordinates
y	array of y coordinates

◆ Subset() [2/3]

DICe::Subset::Subset	(	const int_t	cx,
		const int_t	cy,
		const int_t	width,
		const int_t	height
	)

constructor that takes a centroid and dims as arguments (note this type of subset has not been enabled for obstruction detection, only conformal subsets with defined shapes have this enabled. See the constructor below with a subset_def argument)

Parameters

cx	centroid x pixel location
cy	centroid y pixel location
width	width of the centroid (should be an odd number, otherwise the next larger odd number is used)
height	height of the centroid (should be an odd number, otherwise the next larger odd numer is used)

◆ Subset() [3/3]

DICe::Subset::Subset	(	const int_t	cx,
		const int_t	cy,
		const Conformal_Area_Def &	subset_def
	)

constructor that takes a conformal subset def as the input

Parameters

cx	centroid x pixel location
cy	centroid y pixel location
subset_def	the definition of the subset areas

Member Function Documentation

◆ def_intensities()

intensity_t& DICe::Subset::def_intensities ( const int_t pixel_index )

ref intensities accessor

Parameters

pixel_index the pixel id

◆ grad_x()

const scalar_t& DICe::Subset::grad_x ( const int_t pixel_index ) const

gradient x accessor

Parameters

pixel_index the pixel id note there is no bounds checking

◆ grad_y()

const scalar_t& DICe::Subset::grad_y ( const int_t pixel_index ) const

gradient y accessor

Parameters

pixel_index the pixel id note there is no bounds checking

◆ initialize()

void DICe::Subset::initialize	(	Teuchos::RCP< Image >	image,
		const Subset_View_Target	target = `REF_INTENSITIES`,
		Teuchos::RCP< Local_Shape_Function >	shape_function = `Teuchos::null`,
		const Interpolation_Method	interp = `KEYS_FOURTH`
	)

initialization method:

Parameters

image	the image to get the intensity values from
target	the initialization mode (put the values in the ref or def intensities)
shape_function	contains the deformation map (optional)
interp	interpolation method (optional)

◆ is_obstructed_pixel()

bool DICe::Subset::is_obstructed_pixel	(	const scalar_t &	coord_x,
		const scalar_t &	coord_y
	)		const

EXPERIMENTAL Returns true if the given coordinates fall within an obstructed region for this subset.

Parameters

coord_x	global x-coordinate
coord_y	global y-coordinate

◆ max()

intensity_t DICe::Subset::max ( const Subset_View_Target target = REF_INTENSITIES )

returns the max intensity value

Parameters

target either the reference or deformed intensity values

◆ mean() [1/2]

scalar_t DICe::Subset::mean ( const Subset_View_Target target )

returns the mean intensity value

Parameters

target either the reference or deformed intensity values

◆ mean() [2/2]

scalar_t DICe::Subset::mean	(	const Subset_View_Target	target,
		scalar_t &	sum
	)

returns the mean intensity value

Parameters

target	either the reference or deformed intensity values
sum	[output] returns the reduction value of the intensities minus the mean

◆ min()

intensity_t DICe::Subset::min ( const Subset_View_Target target = REF_INTENSITIES )

returns the min intensity value

Parameters

target either the reference or deformed intensity values

◆ noise_std_dev()

scalar_t DICe::Subset::noise_std_dev	(	Teuchos::RCP< Image >	image,
		Teuchos::RCP< Local_Shape_Function >	shape_function
	)

Returns an estimate of the noise standard deviation for this subset based on the method of J. Immerkaer, Fast Noise Variance Estimation, Computer Vision and Image Understanding, Vol. 64, No. 2, pp. 300-302, Sep. 1996 The estimate is computed for a rectangular window that encompases the entire subset if the subset is conformal.

Parameters

image	the image for which to estimate the noise for this subset
shape_function	contains the deformation map (optional)

◆ ref_intensities()

intensity_t& DICe::Subset::ref_intensities ( const int_t pixel_index )

ref intensities accessor

Parameters

pixel_index the pixel id

◆ turn_off_obstructed_pixels()

void DICe::Subset::turn_off_obstructed_pixels ( Teuchos::RCP< Local_Shape_Function > shape_function )

EXPERIMENTAL Check the deformed position of the pixel to see if it falls inside an obstruction, if so, turn it off.

Parameters

shape_function contains the deformation map (optional)

This method uses the specified deformation map to deform the subset to the current position. It then checks to see if any of the deformed pixels fall behind an obstruction. These obstructed pixels are turned off by setting the is_deactivated_this_step_[i] flag to true. These flags are reset on every frame. When methods like gamma() are called on an objective, these pixels get skipped so they do not contribute to the correlation or the optimization routine.

◆ turn_on_previously_obstructed_pixels()

void DICe::Subset::turn_on_previously_obstructed_pixels ( )

EXPERIMENTAL See if any pixels that were obstructed to begin with are now in view, if so use the newly visible intensity values to reconstruct the subset.

Some pixels in the subset may be hidden in the first frame by an obstruction (or another subset that sits on top of this one). As the frames progress, these pixels eventually become visible. This method can be used to evolve the reference subset intensities by taking the intensity value of the pixel when it becomes visible. The location of the pixel in the current frame is not needed because it is assumed that the reference and deformed subset intensity arrays are ordered the same. So all that needs to be checked is if it was deactivated at frame zero, and is now not deactivated this step, that particular pixel can be used.

◆ write_subset_on_image()

void DICe::Subset::write_subset_on_image	(	const std::string &	file_name,
		Teuchos::RCP< Image >	image,
		Teuchos::RCP< Local_Shape_Function >	shape_function = `Teuchos::null`
	)

draw the subset over an image

Parameters

file_name	the name of the tif file to write
image	pointer to the image to use as the background
shape_function	contains the deformation map (optional)

◆ write_tiff()

void DICe::Subset::write_tiff	(	const std::string &	file_name,
		const bool	use_def_intensities = `false`
	)

write the subset intensity values to a tif file

Parameters

file_name	the name of the tif file to write
use_def_intensities	use the deformed intensities rather than the reference

◆ x()

const int_t& DICe::Subset::x ( const int_t pixel_index ) const

x coordinate accessor

Parameters

pixel_index the pixel id note there is no bounds checking on the index

◆ y()

const int_t& DICe::Subset::y ( const int_t pixel_index ) const

y coordinate accessor

Parameters

pixel_index the pixel id note there is no bounds checking on the index

Member Data Documentation

◆ sub_image_id_

int_t DICe::Subset::sub_image_id_

private

if sub regions of the frame are used instead of reading in the whole sub image, this sub_image_id defines which region to draw the pixel information from

Public Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ Subset() [1/3]

◆ Subset() [2/3]

◆ Subset() [3/3]

Member Function Documentation

◆ def_intensities()

◆ grad_x()

◆ grad_y()

◆ initialize()

◆ is_obstructed_pixel()

◆ max()

◆ mean() [1/2]

◆ mean() [2/2]

◆ min()

◆ noise_std_dev()

◆ ref_intensities()

◆ turn_off_obstructed_pixels()

◆ turn_on_previously_obstructed_pixels()

◆ write_subset_on_image()

◆ write_tiff()

◆ x()

◆ y()

Member Data Documentation

◆ sub_image_id_