lsst::afw::math::Background Class Reference

A virtual base class to evaluate image background levels. More...

#include <Background.h>

Inheritance diagram for lsst::afw::math::Background:

Public Types
using	InternalPixelT = float
	type used for any internal images, and returned by getApproximate

Public Member Functions
	Background (Background const &)=delete
	Background (Background &&)=delete
virtual	~Background ()=default
	dtor
Background &	operator= (Background const &)=delete
Background &	operator= (Background &&)=delete
virtual Background &	operator+= (float const delta)=0
	Add a constant level to a background.
virtual Background &	operator-= (float const delta)=0
	Subtract a constant level from a background.
template<typename PixelT>
std::shared_ptr< lsst::afw::image::Image< PixelT > >	getImage (Interpolate::Style const interpStyle, UndersampleStyle const undersampleStyle=THROW_EXCEPTION) const
	Method to interpolate and return the background for entire image.
template<typename PixelT>
std::shared_ptr< lsst::afw::image::Image< PixelT > >	getImage (std::string const &interpStyle, std::string const &undersampleStyle="THROW_EXCEPTION") const
	Method to interpolate and return the background for entire image.
template<typename PixelT>
std::shared_ptr< lsst::afw::image::Image< PixelT > >	getImage (lsst::geom::Box2I const &bbox, Interpolate::Style const interpStyle, UndersampleStyle const undersampleStyle=THROW_EXCEPTION) const
template<typename PixelT>
std::shared_ptr< lsst::afw::image::Image< PixelT > >	getImage (lsst::geom::Box2I const &bbox, std::string const &interpStyle, std::string const &undersampleStyle="THROW_EXCEPTION") const
template<typename PixelT>
std::shared_ptr< lsst::afw::image::Image< PixelT > >	getImage () const
	Method to interpolate and return the background for entire image.
Interpolate::Style	getAsUsedInterpStyle () const
	Return the Interpolate::Style that we actually used in the last call to getImage()
UndersampleStyle	getAsUsedUndersampleStyle () const
	Return the UndersampleStyle that we actually used in the last call to getImage()
std::shared_ptr< math::Approximate< InternalPixelT > >	getApproximate (ApproximateControl const &actrl, UndersampleStyle const undersampleStyle=THROW_EXCEPTION) const
	Method to return an approximation to the background.
lsst::geom::Box2I	getImageBBox () const
	Return the input image's (PARENT) bounding box.
std::shared_ptr< BackgroundControl >	getBackgroundControl ()
std::shared_ptr< BackgroundControl const >	getBackgroundControl () const

Protected Member Functions
template<typename ImageT>
	Background (ImageT const &img, BackgroundControl const &bgCtrl)
	Constructor for Background.
	Background (lsst::geom::Box2I const imageBBox, int const nx, int const ny)
	Create a Background without any values in it.

Protected Attributes
lsst::geom::Box2I	_imgBBox
	size and origin of input image
std::shared_ptr< BackgroundControl >	_bctrl
	control info set by user.
Interpolate::Style	_asUsedInterpStyle
	the style we actually used
UndersampleStyle	_asUsedUndersampleStyle
	the undersampleStyle we actually used
std::vector< double >	_xcen
	x center pix coords of sub images
std::vector< double >	_ycen
	y center ...
std::vector< int >	_xorig
	x origin pix coords of sub images
std::vector< int >	_yorig
	y origin ...
std::vector< int >	_xsize
	x size of sub images
std::vector< int >	_ysize
	y size ...

Detailed Description

A virtual base class to evaluate image background levels.

Definition at line 236 of file Background.h.

Member Typedef Documentation

InternalPixelT

using lsst::afw::math::Background::InternalPixelT = float

type used for any internal images, and returned by getApproximate

Definition at line 263 of file Background.h.

Constructor & Destructor Documentation

Background() [1/4]

template<typename ImageT>

lsst::afw::math::Background::Background ( ImageT const & img, BackgroundControl const & bgCtrl )

explicitprotected

Constructor for Background.

Estimate the statistical properties of the Image in a grid of cells; we'll later call getImage() to interpolate those values, creating an image the same size as the original

Parameters

img	ImageT (or MaskedImage) whose properties we want
bgCtrl	Control how the Background is estimated

Definition at line 44 of file Background.cc.

        : _imgBBox(img.getBBox()),
          _bctrl(new BackgroundControl(bgCtrl)),
          _asUsedInterpStyle(Interpolate::UNKNOWN),
          _asUsedUndersampleStyle(THROW_EXCEPTION),
          _xcen(0),
          _ycen(0),
          _xorig(0),
          _yorig(0),
          _xsize(0),
          _ysize(0) {
    if (_imgBBox.isEmpty()) {
        throw LSST_EXCEPT(ex::InvalidParameterError, "Image contains no pixels");
    }
 
    // Check that an int's large enough to hold the number of pixels
    if (_imgBBox.getWidth() * static_cast<double>(_imgBBox.getHeight()) > std::numeric_limits<int>::max()) {
        throw LSST_EXCEPT(lsst::pex::exceptions::OverflowError,
                          str(boost::format("Image %dx%d has more pixels than fit in an int (%d)") %
                              _imgBBox.getWidth() % _imgBBox.getHeight() % std::numeric_limits<int>::max()));
    }
 
    _setCenOrigSize(_imgBBox.getWidth(), _imgBBox.getHeight(), bgCtrl.getNxSample(), bgCtrl.getNySample());
}

Background() [2/4]

lsst::afw::math::Background::Background ( lsst::geom::Box2I const imageBBox, int const nx, int const ny )

explicitprotected

Create a Background without any values in it.

Parameters

imageBBox	Bounding box for image to be created by getImage()
nx	Number of samples in x-direction
ny	Number of samples in y-direction

Note

This ctor is mostly used to create a Background given its sample values, and that (in turn) is mostly used to implement persistence.

Definition at line 69 of file Background.cc.

        : _imgBBox(imageBBox),
          _bctrl(new BackgroundControl(nx, ny)),
          _asUsedInterpStyle(Interpolate::UNKNOWN),
          _asUsedUndersampleStyle(THROW_EXCEPTION),
          _xcen(0),
          _ycen(0),
          _xorig(0),
          _yorig(0),
          _xsize(0),
          _ysize(0) {
    if (_imgBBox.isEmpty()) {
        throw LSST_EXCEPT(ex::InvalidParameterError, "Image contains no pixels");
    }
 
    // Check that an int's large enough to hold the number of pixels
    if (_imgBBox.getWidth() * static_cast<double>(_imgBBox.getHeight()) > std::numeric_limits<int>::max()) {
        throw LSST_EXCEPT(lsst::pex::exceptions::OverflowError,
                          str(boost::format("Image %dx%d has more pixels than fit in an int (%d)") %
                              _imgBBox.getWidth() % _imgBBox.getHeight() % std::numeric_limits<int>::max()));
    }
 
    _setCenOrigSize(_imgBBox.getWidth(), _imgBBox.getHeight(), nx, ny);
}

Background() [3/4]

lsst::afw::math::Background::Background ( Background const & )

delete

Background() [4/4]

lsst::afw::math::Background::Background ( Background && )

delete

~Background()

virtual lsst::afw::math::Background::~Background ( )

virtualdefault

dtor

Member Function Documentation

getApproximate()

std::shared_ptr< math::Approximate< InternalPixelT > > lsst::afw::math::Background::getApproximate ( ApproximateControl const & actrl, UndersampleStyle const undersampleStyle = THROW_EXCEPTION ) const

inline

Method to return an approximation to the background.

Parameters

actrl	Approximation style
undersampleStyle	Behaviour if there are too few points

Definition at line 349 of file Background.h.

                                                                             {
        InternalPixelT disambiguate = 0;
        return _getApproximate(actrl, undersampleStyle, disambiguate);
    }

getAsUsedInterpStyle()

Interpolate::Style lsst::afw::math::Background::getAsUsedInterpStyle ( ) const

inline

Return the Interpolate::Style that we actually used in the last call to getImage()

N.b. Interpolate can fallback to a lower order if there aren't enough samples

Definition at line 338 of file Background.h.

{ return _asUsedInterpStyle; }

getAsUsedUndersampleStyle()

UndersampleStyle lsst::afw::math::Background::getAsUsedUndersampleStyle ( ) const

inline

Return the UndersampleStyle that we actually used in the last call to getImage()

Definition at line 342 of file Background.h.

{ return _asUsedUndersampleStyle; }

getBackgroundControl() [1/2]

std::shared_ptr< BackgroundControl > lsst::afw::math::Background::getBackgroundControl ( )

inline

Definition at line 360 of file Background.h.

{ return _bctrl; }

getBackgroundControl() [2/2]

std::shared_ptr< BackgroundControl const > lsst::afw::math::Background::getBackgroundControl ( ) const

inline

Definition at line 361 of file Background.h.

{ return _bctrl; }

getImage() [1/5]

template<typename PixelT>

std::shared_ptr< lsst::afw::image::Image< PixelT > > lsst::afw::math::Background::getImage ( ) const

inline

Method to interpolate and return the background for entire image.

Definition at line 330 of file Background.h.

                                                              {
        return getImage<PixelT>(_bctrl->getInterpStyle(), _bctrl->getUndersampleStyle());
    }

getImage() [2/5]

template<typename PixelT>

std::shared_ptr< lsst::afw::image::Image< PixelT > > lsst::afw::math::Background::getImage ( Interpolate::Style const interpStyle, UndersampleStyle const undersampleStyle = THROW_EXCEPTION ) const

inline

Method to interpolate and return the background for entire image.

Parameters

interpStyle	Style of the interpolation
undersampleStyle	Behaviour if there are too few points

Returns

A boost shared-pointer to an image containing the estimated background

Definition at line 284 of file Background.h.

                                                                             {
        return getImage<PixelT>(_imgBBox, interpStyle, undersampleStyle);
    }

getImage() [3/5]

template<typename PixelT>

std::shared_ptr< lsst::afw::image::Image< PixelT > > lsst::afw::math::Background::getImage ( lsst::geom::Box2I const & bbox, Interpolate::Style const interpStyle, UndersampleStyle const undersampleStyle = THROW_EXCEPTION ) const

inline

Parameters

bbox	Bounding box for sub-image
interpStyle	Style of the interpolation
undersampleStyle	Behaviour if there are too few points

Definition at line 308 of file Background.h.

                                                                             {
        return _getImage(bbox, interpStyle, undersampleStyle, static_cast<PixelT>(0));
    }

getImage() [4/5]

template<typename PixelT>

std::shared_ptr< lsst::afw::image::Image< PixelT > > lsst::afw::math::Background::getImage ( lsst::geom::Box2I const & bbox, std::string const & interpStyle, std::string const & undersampleStyle = "THROW_EXCEPTION" ) const

inline

Parameters

bbox	Bounding box for sub-image
interpStyle	Style of the interpolation
undersampleStyle	Behaviour if there are too few points

Definition at line 319 of file Background.h.

                                                                         {
        return _getImage(bbox, math::stringToInterpStyle(interpStyle),
                         stringToUndersampleStyle(undersampleStyle), static_cast<PixelT>(0));
    }

getImage() [5/5]

template<typename PixelT>

std::shared_ptr< lsst::afw::image::Image< PixelT > > lsst::afw::math::Background::getImage ( std::string const & interpStyle, std::string const & undersampleStyle = "THROW_EXCEPTION" ) const

inline

Method to interpolate and return the background for entire image.

Parameters

interpStyle	Style of the interpolation
undersampleStyle	Behaviour if there are too few points

Returns

A boost shared-pointer to an image containing the estimated background

Definition at line 297 of file Background.h.

                                                                                                       {
        return getImage<PixelT>(math::stringToInterpStyle(interpStyle),
                                stringToUndersampleStyle(undersampleStyle));
    }

getImageBBox()

lsst::geom::Box2I lsst::afw::math::Background::getImageBBox ( ) const

inline

Return the input image's (PARENT) bounding box.

Definition at line 358 of file Background.h.

{ return _imgBBox; }

operator+=()

virtual Background & lsst::afw::math::Background::operator+= ( float const delta )

pure virtual

Add a constant level to a background.

Implemented in lsst::afw::math::BackgroundMI.

operator-=()

virtual Background & lsst::afw::math::Background::operator-= ( float const delta )

pure virtual

Subtract a constant level from a background.

Implemented in lsst::afw::math::BackgroundMI.

operator=() [1/2]

Background & lsst::afw::math::Background::operator= ( Background && )

delete

operator=() [2/2]

Background & lsst::afw::math::Background::operator= ( Background const & )

delete

Member Data Documentation

_asUsedInterpStyle

Interpolate::Style lsst::afw::math::Background::_asUsedInterpStyle

mutableprotected

the style we actually used

Definition at line 366 of file Background.h.

_asUsedUndersampleStyle

UndersampleStyle lsst::afw::math::Background::_asUsedUndersampleStyle

mutableprotected

the undersampleStyle we actually used

Definition at line 367 of file Background.h.

_bctrl

std::shared_ptr<BackgroundControl> lsst::afw::math::Background::_bctrl

protected

control info set by user.

Definition at line 365 of file Background.h.

_imgBBox

lsst::geom::Box2I lsst::afw::math::Background::_imgBBox

protected

size and origin of input image

Definition at line 364 of file Background.h.

_xcen

std::vector<double> lsst::afw::math::Background::_xcen

protected

x center pix coords of sub images

Definition at line 369 of file Background.h.

_xorig

std::vector<int> lsst::afw::math::Background::_xorig

protected

x origin pix coords of sub images

Definition at line 371 of file Background.h.

_xsize

std::vector<int> lsst::afw::math::Background::_xsize

protected

x size of sub images

Definition at line 373 of file Background.h.

_ycen

std::vector<double> lsst::afw::math::Background::_ycen

protected

y center ...

Definition at line 370 of file Background.h.

_yorig

std::vector<int> lsst::afw::math::Background::_yorig

protected

y origin ...

Definition at line 372 of file Background.h.

_ysize

std::vector<int> lsst::afw::math::Background::_ysize

protected

y size ...

Definition at line 374 of file Background.h.

---

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

• /j/snowflake/release/lsstsw/stack/lsst-scipipe-12.0.0/Linux/afw/g083dd6704c+a047e97985/include/lsst/afw/math/Background.h
• /j/snowflake/release/lsstsw/stack/lsst-scipipe-12.0.0/Linux/afw/g083dd6704c+a047e97985/src/math/Background.cc