Image structure that can be manipulated and exported to/from fits files. More...

#include <image_processing.h>

Public Member Functions
	PixelMap (const PixelMap &pmap, double res_ratio)
	Creates a PixelMap at a different resolution. The new counts are calculated integrating over the input pixels. No interpolation or smoothing is performed. More...

	PixelMap (const PixelMap &other)

	PixelMap (PixelMap &&other)

	PixelMap (const PixelMap &pmap, const double *center, std::size_t Npixels)
	Creates a new PixelMap from a square region of a PixelMap. If the region exceeds the boundaries of the original map, the new map is completed with zeros. More...

	PixelMap (const PixelMap &pmap, long nx, long ny, std::size_t Npixels)
	Produces a square cut-out of the input PixelMap. More...

	PixelMap (const double *center, std::size_t Npixels, double resolution, PixelMapUnits u=PixelMapUnits::ndef)
	make square PixelMap More...

	PixelMap (const double *center, std::size_t Nx, std::size_t Ny, double resolution, PixelMapUnits u=PixelMapUnits::ndef)
	make rectangular PixelMap with square pixels More...

	PixelMap (std::string fitsfilename, double resolution=-1, PixelMapUnits u=PixelMapUnits::ndef)
	Constructs a PixelMap reading in a fits file Infos about resolution, Npixels and center are read from the header. More...

PixelMap &	operator= (const PixelMap &other)

PixelMap &	operator= (PixelMap &&other)

void	ChangeUnits (PixelMapUnits u)

PixelMapUnits	getUnits () const

bool	valid () const

std::size_t	size () const

std::size_t	getNx () const

std::size_t	getNy () const

double	getRangeX () const

double	getRangeY () const

void const	getCenter (Point_2d &c) const

Point_2d	getCenter () const

double	getResolution () const

double	getRA ()
	returns right accention of center

double	getDEC ()
	returns declination of center

void	setRAandDec (double RAin, double DECin)
	set the coordinates of center

void	Clean ()

void	AddImages (ImageInfo *imageinfo, int Nimages, float rescale=1.)
	Add an image to the map. More...

void	AddImages (std::vector< ImageInfo > &imageinfo, int Nimages, float rescale=1.)

void	AddGridBrightness (Grid &grid)
	Add an image from a the surface brightnesses of a Grid to the PixelMap.

void	AddGridMapBrightness (const GridMap &grid)
	Add an image from a the surface brightnesses of a GridMap to the PixelMap.

void	AddUniformImages (ImageInfo *imageinfo, int Nimages, double value)
	Add images with uniform surface brightness set by input parameter value. More...

PosType	AddSource (Source &source)

PosType	AddSource (Source &source, int oversample)
	Add a source to the pixel map by oversamples the source so that oversample^2 points within each pixel are averaged.

void	AddPointSource (const Point_2d &x, double flux)

void	copy_in (const PixelMap &pmap)
	copy a PixelMap into this one. More...

void	paste (const PixelMap &pmap)
	Replace overlaping pixel values with those of the input map. More...

void	paste (const PixelMap &pmap, long nx, long ny)
	paste a PixelMap on with the lower left pixel match to [nx,ny] of this

void	duplicate (const PixelMap &pmap)
	copy a PixelMap that must be the same without creating a new one.. More...

template<typename T >
PosType	AddSource_parallel (T &source, int oversample)
	Adds source to map. This version breaks pixels up into blocks and does them in seporate threads.

void	AddCurve (ImageInfo *curve, double value)
	Draws a closed curve through the points in curve->imagekist. More...

void	AddCurve (Kist< Point > *imagekist, PosType value)

void	AddCurve (std::vector< Point_2d > &curve, double value)

void	AddCurve (std::vector< RAY > &curve, double value)

void	drawline (double x1[], double x2[], double value, bool add)
	simple line More...

void	DrawLine (long x0, long x1, long y0, long y1, double value, bool add)
	line by Bresenham's line algorithm

void	DrawLineGS (long x0, long x1, long y0, long y1, double value, bool add)

void	drawcircle (PosType r_center[], PosType radius, PosType value)
	Draws a circle. More...

void	drawdisk (PosType r_center[], PosType radius, PosType value, int Nstrip)
	Draws a disk. More...

void	AddGrid (const Grid &grid, double value=1.0)
	Fills in pixels where the image plane points in the grid are located with the value given. More...

void	AddGrid (const Grid &grid, LensingVariable val)
	Fills in pixels with the selected quantity from the grid points. More...

void	Renormalize (double factor)
	Multiplies the whole map by a scalar factor.

void	AddValue (std::size_t i, double value)
	Adds a value to the i-th pixel.

void	AssignValue (std::size_t i, double value)
	Assigns a value to the i-th pixel.

void	printASCII () const
	Print an ASCII table of all the pixel values.

void	printASCIItoFile (std::string filename) const
	Print an ASCII table of all the pixel values.

void	printFITS (std::string filename, bool Xflip=false, bool verbose=false)
	Output the pixel map as a fits file.

void	printFITS (std::string filename, std::vector< std::tuple< std::string, double, std::string > > &extra_header_info, bool verbose)

void	printFITS (std::string filename, std::vector< std::string > &headercards)
	This overides all header information and relaces it with the inputs. Meant for making a modified copy. More...

void	smooth (double sigma)
	Smoothes a map with a Gaussian kernel of width sigma (in arcseconds)

double	getValue (std::size_t i) const

double &	operator[] (std::size_t i)

double	operator[] (std::size_t i) const

double	operator() (std::size_t i) const

double	operator() (std::size_t i, std::size_t j) const

double &	operator() (std::size_t i, std::size_t j)

PixelMap &	operator+= (const PixelMap &rhs)
	Add the values of another PixelMap to this one.

void	operator+= (double f)

PixelMap	operator+ (const PixelMap &) const
	Add two PixelMaps.

PixelMap &	operator-= (const PixelMap &rhs)
	Subtract the values of another PixelMap from this one.

PixelMap	operator- (const PixelMap &) const
	Subtract two PixelMaps.

PixelMap &	operator*= (const PixelMap &rhs)
	Multiply the values of another PixelMap by this one.

PixelMap	operator* (const PixelMap &a) const
	Multiply two PixelMaps.

PixelMap	operator/ (const PixelMap &a) const
	Multiply two PixelMaps.

PixelMap &	*operator=** (PosType b)

PixelMap	operator* (PosType b) const

std::valarray< double > &	data ()

bool	agrees (const PixelMap &other) const
	Check whether two PixelMaps agree in their physical dimensions.

PosType	ave () const
	return average pixel value

PosType	sum () const
	return sum of all pixel values

size_t	size ()
	Total number of pixels.

double	max () const

double	min () const

void	FindArc (PosType &radius, PosType xc, PosType arc_center, PosType &arclength, PosType &width, PosType threshold)
	Find arcs in image WARNING: THIS IS UNDER CONSTRUCTION!

long	find_index (PosType const x[], long &ix, long &iy) const
	get the index for a position, returns -1 if out of map, this version returns the 2D grid coordinates More...

long	find_index (PosType const x[]) const
	get the index for a position, returns -1 if out of map

long	find_index (PosType x, PosType y, long &ix, long &iy) const
	get the index for a position, returns -1 if out of map, this version returns the 2D grid coordinates More...

long	find_index (PosType x, PosType y) const
	get the index for a position, returns -1 if out of map

void	find_position (PosType x[], std::size_t const index) const
	get the index for a position, returns -1 if out of map

void	find_position (PosType x[], std::size_t const ix, std::size_t const iy) const
	get the index for a position, returns -1 if out of map

PixelMap	rotate (PosType theta, PosType scale=1)
	rotate and scale the image while keeping pixels, resoluiton More...

PosType	linear_interpolate (PosType x[])
	interpolate to point x[] More...

void	drawgrid (int N, PosType value)
	draw a grid on the image that divides the each demension into N cells More...

void	drawPoints (std::vector< Point * > points, PosType size, PosType value)

void	drawPoints (std::vector< Point > points, PosType size, PosType value)

void	drawCurve (std::vector< Point * > points, PosType value)

void	drawCurve (std::vector< Point > points, PosType value)

void	drawPoints (std::vector< Point_2d > points, PosType size, PosType value)

void	drawCurve (std::vector< Point_2d > points, PosType value)

void	drawSquare (PosType p1[], PosType p2[], PosType value)
	Draw a rectangle. More...

void	drawBox (PosType p1[], PosType p2[], PosType value, int Nstrip)
	Draws a box (filling the inside with horizontal lines, starting from the top)

void	PowerSpectrum (std::vector< PosType > &power_spectrum, std::vector< PosType > &lvec, bool overwrite=true)
	Find the power spectrum of the map. More...

void	PowerSpectrum (std::vector< PosType > &power_spectrum, const std::vector< PosType > &lbins, std::vector< PosType > &lave, bool overwrite=true)
	Find the power spectrum of the map. More...

void	AdaptiveSmooth (PosType value)

void	find_contour (double level, std::vector< std::vector< Point_2d > > &points, std::vector< bool > &hits_edge) const
	returns a vector of contour curves

void	find_islands_holes (double level, std::vector< std::vector< size_t > > &points) const

void	lens_definition (double min_sn_per_image, double pixel_threshold, int &Nimages, double &total_sig_noise_source, std::vector< size_t > &maxima_indexes, std::vector< std::vector< size_t > > &image_points, bool &lens_TF, double &level, size_t &n_pix_in_source, bool verbose=false)

std::vector< size_t >	maxima (double minlevel) const
	find maxima that are above minlevel More...

int	count_islands (std::vector< size_t > &pixel_index) const
	For a list of pixel indexes this will count and separated islands that are not connected. More...

size_t	threshold (std::list< size_t > &pixel_index, PosType value)
	get a list of pixels above value

void	flipY ()
	reflects the image about the horizontal mid-line

void	flipX ()
	reflects the image about the vertical mid-line

void	doubleFlip ()
	rotate the image by 180deg or equivalently reflect it through the origin

void	recenter (PosType newcenter[2])
	recenter the map without changing anything else. More...

void	recenter (Point_2d newcenter)

void	convolve (PixelMap &kernel, long center_x=0, long center_y=0)
	convolve the image with a kernel. More...

PixelMap	downsize (int n)
	Creates a PixelMap with a lower resolution. The value of the pixels are added for the new pixels. If n does not go into the orginial number of pixels evenly the right (top) redge is dropped. More...

void	addheader (std::string label, long value, std::string comment)
	add a heaader keyword that will appear in fits output

void	addheader (std::string label, size_t value, std::string comment)

void	addheader (std::string label, float value, std::string comment)

void	addheader (std::string label, double value, std::string comment)

void	addheader (std::string label, std::string value, std::string comment)

Static Public Member Functions
static void	swap (PixelMap &, PixelMap &)

Friends
void	swap (PixelMap &, PixelMap &)

Detailed Description

Image structure that can be manipulated and exported to/from fits files.

Constructor & Destructor Documentation

◆ PixelMap() [1/6]

PixelMap::PixelMap	(	const PixelMap &	pmap,
		double	res_ratio
	)

Creates a PixelMap at a different resolution. The new counts are calculated integrating over the input pixels. No interpolation or smoothing is performed.

Parameters

res_ratio resolution of map is res_ratio times the resolution of the input map

◆ PixelMap() [2/6]

PixelMap::PixelMap	(	const PixelMap &	pmap,
		const double *	center,
		std::size_t	my_Npixels
	)

Creates a new PixelMap from a square region of a PixelMap. If the region exceeds the boundaries of the original map, the new map is completed with zeros.

Parameters

center	Input PixelMap (from which the stamp is taken)
my_Npixels	center of the region to be duplicated (in rads) size of the region to be duplicated (in pixels)

◆ PixelMap() [3/6]

PixelMap::PixelMap	(	const PixelMap &	pmap,
		long	nx,
		long	ny,
		std::size_t	my_Npixels
	)

Produces a square cut-out of the input PixelMap.

Parameters

nx	Input PixelMap (from which the stamp is taken)
ny	lower left pixels of in pmap
my_Npixels	lower left pixels of in pmap size of the region to be duplicated (in pixels)

◆ PixelMap() [4/6]

PixelMap::PixelMap	(	const double *	center,
		std::size_t	Npixels,
		double	resolution,
		PixelMapUnits	u = `PixelMapUnits::ndef`
	)

make square PixelMap

Parameters

Npixels	The location of the center of the map
resolution	Number of pixels in one dimension of map. One dimensional range of map in whatever units the point positions are in

◆ PixelMap() [5/6]

PixelMap::PixelMap	(	const double *	center,
		std::size_t	Nx,
		std::size_t	Ny,
		double	resolution,
		PixelMapUnits	u = `PixelMapUnits::ndef`
	)

make rectangular PixelMap with square pixels

Parameters

Nx	The location of the center of the map
Ny	Number of pixels in x dimension of map.
resolution	Number of pixels in y dimension of map. One dimensional range of map in whatever units the point positions are in

◆ PixelMap() [6/6]

PixelMap::PixelMap	(	std::string	fitsfilename,
		double	my_res = `-1`,
		PixelMapUnits	u = `PixelMapUnits::ndef`
	)

Constructs a PixelMap reading in a fits file Infos about resolution, Npixels and center are read from the header.

Parameters

fitsfilename	file name of fits file to be read
my_res	resolution (rad) of fits image if not given in fits file, use default or -1 otherwise

Member Function Documentation

◆ AddCurve()

void PixelMap::AddCurve	(	ImageInfo *	curve,
		double	value
	)

Draws a closed curve through the points in curve->imagekist.

This differs form PixelMap::AddImage() in that it draws lines between the points and takes no account of the cells that the points are in or the surface brightness. The points must be ordered already. Particularly useful for drawing the caustics that may have irregular cell sizes. The last point will be connected to the first point.

◆ AddGrid() [1/2]

void PixelMap::AddGrid	(	const Grid &	grid,
		double	value = `1.0`
	)

Fills in pixels where the image plane points in the grid are located with the value given.

This is for lensing quantities and not surface brightness. If you want surface brightness use PixelMap::AddGridBrightness()

◆ AddGrid() [2/2]

void PixelMap::AddGrid	(	const Grid &	grid,
		LensingVariable	val
	)

Fills in pixels with the selected quantity from the grid points.

The grid and PixelMap do not need to be related in any way. Using this function multiple grids can be added to the same image.

This is for lensing quantities and not surface brightness. If you want surface brightness use PixelMap::AddGridBrightness()

Warning: When adding a new grid it should not overlap with any of the previously added grids.

◆ AddImages() [1/2]

void PixelMap::AddImages	(	ImageInfo *	imageinfo,
		int	Nimages,
		float	rescale = `1.`
	)

Add an image to the map.

If rescale==0 gives constant surface brightness, if < 0 the surface brightness is not scaled by the pixel area as for the flux (default: 1). Negative values are good for mapping some quantity independant of the pixel size

Parameters

imageinfo	An array of ImageInfo-s. There is no reason to separate images for this routine
Nimages	Number of images on input.
rescale	rescales the surface brightness while leaving the image unchanged, see full notes

◆ AddImages() [2/2]

void PixelMap::AddImages	(	std::vector< ImageInfo > &	imageinfo,
		int	Nimages,
		float	rescale = `1.`
	)

Parameters

imageinfo	An array of ImageInfo-s. There is no reason to separate images for this routine
Nimages	Number of images on input.
rescale	rescales the surface brightness while leaving the image unchanged, see full notes

◆ AddUniformImages()

void PixelMap::AddUniformImages	(	ImageInfo *	imageinfo,
		int	Nimages,
		double	value
	)

Add images with uniform surface brightness set by input parameter value.

This does not use the surface brightnesses stored in the image points.

Parameters

imageinfo An array of ImageInfo-s. There is no reason to separate images for this routine

◆ convolve()

void PixelMap::convolve	(	PixelMap &	kernel,
		long	center_x = `0`,
		long	center_y = `0`
	)

convolve the image with a kernel.

It is assumed that the size of the kernel is much smaller than the image and that the kernal has the same pixel size as the image.

◆ copy_in()

void PixelMap::copy_in ( const PixelMap & pmap )

copy a PixelMap into this one.

The size, resolution and center of the pixel maps are not changed and do not need to match. The input pixel map is added while conserving the area integral of the map within the area of overlaping pixels.

◆ count_islands()

int PixelMap::count_islands ( std::vector< size_t > & pixel_index ) const

For a list of pixel indexes this will count and separated islands that are not connected.

On return, 'pixel_index' is ordered into groups and the 'heads' list points to the first elemant in each group plus the end of the list so that heads[i] to heads[i+1] is a group for 0 <= i <= ngroups. The number of groups is returned which is also heads.size() - 1

◆ downsize()

PixelMap PixelMap::downsize ( int n )

Creates a PixelMap with a lower resolution. The value of the pixels are added for the new pixels. If n does not go into the orginial number of pixels evenly the right (top) redge is dropped.

Parameters

n	number of pixels each direction added into each new pixel

◆ drawcircle()

void PixelMap::drawcircle	(	PosType	r_center[],
		PosType	radius,
		PosType	value
	)

Draws a circle.

Parameters

r_center	center of circle
radius	radius of circle
value	value that it is set to on the map

◆ drawdisk()

void PixelMap::drawdisk	(	PosType	r_center[],
		PosType	radius,
		PosType	value,
		int	Nstrip
	)

Draws a disk.

Parameters

r_center	center of disk
radius	radius of disk
value	value that it is set to on the map
Nstrip	number of lines we want

◆ drawgrid()

void PixelMap::drawgrid	(	int	N,
		PosType	value
	)

draw a grid on the image that divides the each demension into N cells

Draws a grid.

◆ drawline()

void PixelMap::drawline	(	double	x1[],
		double	x2[],
		double	value,
		bool	add
	)

simple line

Draws a line between two points on the image by setting the pixels equal to value.

TODO: Could be improved by detecting if the line passes through the map at all before starting. Could also be improved by making the line fatter by including neighbor points.

Parameters

x1	one end point of line
x2	other end point of line
value	value that it is set to on the map
add	true : add value, false replace with value

◆ drawSquare()

void PixelMap::drawSquare	(	PosType	p1[],
		PosType	p2[],
		PosType	value
	)

Draw a rectangle.

Draws a square.

◆ duplicate()

void PixelMap::duplicate ( const PixelMap & pmap )

copy a PixelMap that must be the same without creating a new one..

This avoids calling a any constructor or destructor.

◆ find_index() [1/2]

long PixelMap::find_index	(	PosType const	x[],
		long &	ix,
		long &	iy
	)		const

get the index for a position, returns -1 if out of map, this version returns the 2D grid coordinates

get the index for a position, returns -1 if out of map

◆ find_index() [2/2]

long PixelMap::find_index	(	PosType	x,
		PosType	y,
		long &	ix,
		long &	iy
	)		const

get the index for a position, returns -1 if out of map, this version returns the 2D grid coordinates

get the index for a position, returns -1 if out of map

◆ find_islands_holes()

void PixelMap::find_islands_holes	(	double	level,
		std::vector< std::vector< size_t > > &	points
	)		const

find all the points above level divided into seprated groups

Groups with points are connected regions above level. Groups without points are regions surrounded by regions above level, i.e. holes.

◆ lens_definition()

void PixelMap::lens_definition	(	double	min_sn_per_image,
		double	pixel_threshold,
		int &	Nimages,
		double &	total_sig_noise_source,
		std::vector< size_t > &	maxima_indexes,
		std::vector< std::vector< size_t > > &	image_points,
		bool &	lens_TF,
		double &	level,
		size_t &	n_pix_in_source,
		bool	verbose = `false`
	)

This applies a definition of lesning for a resolved source based on that of Sonnenfeld et al. 2023

This is meant to be used on a signal-to-noise map of the lensed source only.

The definition does the following tests: 1) define a footprint at surface brightness level pixel_threshold 2) romove disconected region that have signal-to-noise below min_sn_per_image 3) if there are multiple images or a hole in the image lens_TF =true 4) if there is one image with no hole increase the threshold and apply 3) until the it is classified as a lens or it reaches the maximum surface brightness level

Parameters

min_sn_per_image	signal-to-noise required for a seporate image (ex 10)
pixel_threshold	signal-to-noise threshold that defines the footprint (ex. 2)
Nimages	the number of images
total_sig_noise_source	gives the total signal-to-noise of all images
maxima_indexes	index of maxima
lens_TF	whether it passes lens diffintion
level	levels on which the multiple images are defined
n_pix_in_source	number of pixels in footprint

◆ linear_interpolate()

PosType PixelMap::linear_interpolate ( PosType x[] )

interpolate to point x[]

bilinear interpolation

◆ maxima()

std::vector< size_t > PixelMap::maxima ( double minlevel ) const

find maxima that are above minlevel

find the index of the pixels that are larger than all its neighbors

◆ paste()

void PixelMap::paste ( const PixelMap & pmap )

Replace overlaping pixel values with those of the input map.

No attempt is made to interpolate or average the pixels of pmap. No integration is done. If the resolution of input map is higher than the reslution of the map then the pixels values will just be that of the last pixel visited while going through them.

This can be used to sew tiles together into a larger map.

◆ PowerSpectrum() [1/2]

void PixelMap::PowerSpectrum	(	std::vector< PosType > &	power_spectrum,
		const std::vector< PosType > &	lbins,
		std::vector< PosType > &	lave,
		bool	overwrite = `true`
	)

inline

Find the power spectrum of the map.

Parameters

power_spectrum	output power spectrum
lbins	output l values of bands
lave	output l values of bands
overwrite	if false add power to existing power_spectrum (used for averaging over many fields

◆ PowerSpectrum() [2/2]

void PixelMap::PowerSpectrum	(	std::vector< PosType > &	power_spectrum,
		std::vector< PosType > &	lvec,
		bool	overwrite = `true`
	)

inline

Find the power spectrum of the map.

Parameters

power_spectrum	output power spectrum
lvec	output l values of bands
overwrite	if false add power to existing power_spectrum (used for averaging over many fields

◆ printFITS()

void PixelMap::printFITS	(	std::string	filename,
		std::vector< std::string > &	headercards
	)

This overides all header information and relaces it with the inputs. Meant for making a modified copy.

Parameters

filename	file to create
headercards	header information in cfitsio "card" format

◆ recenter() [1/2]

void PixelMap::recenter ( Point_2d newcenter )

Parameters

newcenter in radians

◆ recenter() [2/2]

void PixelMap::recenter ( PosType newcenter[2] )

recenter the map without changing anything else.

Parameters

newcenter in radians

◆ rotate()

PixelMap PixelMap::rotate	(	PosType	theta,
		PosType	scale = `1`
	)

rotate and scale the image while keeping pixels, resoluiton

Parameters

theta	counter-clockwise rotation (radians)
scale	scale <1 shrinks it

The documentation for this class was generated from the following files:

SLsimLib/include/image_processing.h
SLsimLib/ImageProcessing/pixelize.cpp

Public Member Functions

Static Public Member Functions

Friends

Detailed Description

Constructor & Destructor Documentation

◆ PixelMap() [1/6]

◆ PixelMap() [2/6]

◆ PixelMap() [3/6]

◆ PixelMap() [4/6]

◆ PixelMap() [5/6]

◆ PixelMap() [6/6]

Member Function Documentation

◆ AddCurve()

◆ AddGrid() [1/2]

◆ AddGrid() [2/2]

◆ AddImages() [1/2]

◆ AddImages() [2/2]

◆ AddUniformImages()

◆ convolve()

◆ copy_in()

◆ count_islands()

◆ downsize()

◆ drawcircle()

◆ drawdisk()

◆ drawgrid()

◆ drawline()

◆ drawSquare()

◆ duplicate()

◆ find_index() [1/2]

◆ find_index() [2/2]

◆ find_islands_holes()

◆ lens_definition()

◆ linear_interpolate()

◆ maxima()

◆ paste()

◆ PowerSpectrum() [1/2]

◆ PowerSpectrum() [2/2]

◆ printFITS()

◆ recenter() [1/2]

◆ recenter() [2/2]

◆ rotate()