lsst::meas::algorithms::PsfCandidate< PixelT > Class Template Reference

Class stored in SpatialCells for spatial Psf fitting. More...

#include <PsfCandidate.h>

Inheritance diagram for lsst::meas::algorithms::PsfCandidate< PixelT >:

Public Types
typedef boost::shared_ptr < PsfCandidate< PixelT > >	Ptr
typedef boost::shared_ptr < const PsfCandidate< PixelT > >	ConstPtr
typedef std::vector< Ptr >	PtrList
typedef lsst::afw::image::MaskedImage < PixelT >	MaskedImageT
Public Types inherited from lsst::afw::math::SpatialCellMaskedImageCandidate< PixelT >
typedef boost::shared_ptr < SpatialCellMaskedImageCandidate >	Ptr
typedef boost::shared_ptr < const SpatialCellMaskedImageCandidate >	ConstPtr
Public Types inherited from lsst::afw::math::SpatialCellCandidate
enum	Status { BAD = 0, GOOD = 1, UNKNOWN = 2 }
typedef boost::shared_ptr < SpatialCellCandidate >	Ptr
typedef boost::shared_ptr < const SpatialCellCandidate >	ConstPtr

Public Member Functions
	PsfCandidate (boost::shared_ptr< afw::table::SourceRecord > const &source, boost::shared_ptr< afw::image::Exposure< PixelT > const > parentExposure)
	PsfCandidate (boost::shared_ptr< afw::table::SourceRecord > const &source, boost::shared_ptr< afw::image::Exposure< PixelT > const > parentExposure, double xCenter, double yCenter)
virtual	~PsfCandidate ()
	Destructor. More...
double	getCandidateRating () const
boost::shared_ptr < afw::table::SourceRecord >	getSource () const
	Return the original Source. More...
double	getAmplitude () const
	Return the best-fit amplitude. More...
void	setAmplitude (double amplitude)
	Set the best-fit amplitude. More...
double	getVar () const
	Return the variance in use when fitting this object. More...
void	setVar (double var)
	Set the variance to use when fitting this object. More...
boost::shared_ptr < afw::image::MaskedImage < PixelT > const >	getMaskedImage () const
boost::shared_ptr < afw::image::MaskedImage < PixelT > const >	getMaskedImage (int width, int height) const
boost::shared_ptr < afw::image::MaskedImage < PixelT > >	getOffsetImage (std::string const algorithm, unsigned int buffer) const
	Return an offset version of the image of the source. The returned image has been offset to put the centre of the object in the centre of a pixel. More...
Public Member Functions inherited from lsst::afw::math::SpatialCellMaskedImageCandidate< PixelT >
	SpatialCellMaskedImageCandidate (float const xCenter, float const yCenter)
	ctor More...
virtual	~SpatialCellMaskedImageCandidate ()
double	getChi2 () const
	Return the candidate's chi^2. More...
void	setChi2 (double chi2)
	Set the candidate's chi^2. More...
Public Member Functions inherited from lsst::afw::math::SpatialCellCandidate
	SpatialCellCandidate (float const xCenter, float const yCenter)
virtual	~SpatialCellCandidate ()
float	getXCenter () const
	Return the object's column-centre. More...
float	getYCenter () const
	Return the object's row-centre. More...
virtual bool	instantiate ()
	Do anything needed to make this candidate usable. More...
virtual void	setCandidateRating (double)
	Set the candidate's rating. More...
int	getId () const
	Return the candidate's unique ID. More...
Status	getStatus () const
	Return the candidate's status. More...
void	setStatus (Status status)
	Set the candidate's status. More...
virtual bool	isBad () const
	Is this candidate unacceptable? More...

Static Public Member Functions
static int	getBorderWidth ()
	Return the number of pixels being ignored around the candidate image's edge. More...
static void	setBorderWidth (int border)
	Set the number of pixels to ignore around the candidate image's edge. More...
static void	setPixelThreshold (float threshold)
static float	getPixelThreshold ()
	Get threshold for rejecting pixels unconnected with the central footprint. More...
static void	setMaskBlends (bool doMaskBlends)
	Set whether blends are masked. More...
static bool	getMaskBlends ()
	Get whether blends are masked. More...
Static Public Member Functions inherited from lsst::afw::math::SpatialCellMaskedImageCandidate< PixelT >
static void	setWidth (int width)
	Set the width of the image that getImage should return. More...
static int	getWidth ()
	Return the width of the image that getImage should return. More...
static void	setHeight (int height)
	Set the height of the image that getImage should return. More...
static int	getHeight ()
	Return the height of the image that getImage should return. More...

Private Member Functions
boost::shared_ptr < afw::image::MaskedImage < PixelT > >	offsetImage (boost::shared_ptr< afw::image::MaskedImage< PixelT > > img, std::string const algorithm, unsigned int buffer)
boost::shared_ptr < afw::image::MaskedImage < PixelT > >	extractImage (unsigned int width, unsigned int height) const

Private Attributes
boost::shared_ptr < lsst::afw::image::Exposure < PixelT > const >	_parentExposure
boost::shared_ptr < afw::image::MaskedImage < PixelT > >	_offsetImage
boost::shared_ptr < afw::table::SourceRecord >	_source
bool	_haveImage
double	_amplitude
double	_var
afw::geom::Point2D	_xyCenter

Static Private Attributes
static int	_border = 0
static int	_defaultWidth = 21
static float	_pixelThreshold = 0.0
	Threshold for masking pixels unconnected with central footprint. More...
static bool	_doMaskBlends = true
	Mask blends when extracting? More...

Additional Inherited Members
Protected Attributes inherited from lsst::afw::math::SpatialCellMaskedImageCandidate< PixelT >
boost::shared_ptr < lsst::afw::image::MaskedImage < PixelT > lsst::afw::image::MaskPixel, lsst::afw::image::VariancePixel >	_image
	a pointer to the MaskedImage, for the use of the base class More...

Detailed Description

template<typename PixelT>
class lsst::meas::algorithms::PsfCandidate< PixelT >

Class stored in SpatialCells for spatial Psf fitting.

PsfCandidate is a detection that may turn out to be a PSF. We'll assign them to sets of SpatialCells; these sets will then be used to fit a spatial model to the PSF.

Definition at line 57 of file PsfCandidate.h.

Member Typedef Documentation

template<typename PixelT>

typedef boost::shared_ptr<const PsfCandidate<PixelT> > lsst::meas::algorithms::PsfCandidate< PixelT >::ConstPtr

Definition at line 66 of file PsfCandidate.h.

template<typename PixelT>

typedef lsst::afw::image::MaskedImage<PixelT> lsst::meas::algorithms::PsfCandidate< PixelT >::MaskedImageT

Definition at line 69 of file PsfCandidate.h.

template<typename PixelT>

typedef boost::shared_ptr<PsfCandidate<PixelT> > lsst::meas::algorithms::PsfCandidate< PixelT >::Ptr

Definition at line 65 of file PsfCandidate.h.

template<typename PixelT>

typedef std::vector<Ptr > lsst::meas::algorithms::PsfCandidate< PixelT >::PtrList

Definition at line 67 of file PsfCandidate.h.

Constructor & Destructor Documentation

template<typename PixelT>

lsst::meas::algorithms::PsfCandidate< PixelT >::PsfCandidate ( boost::shared_ptr< afw::table::SourceRecord > const &  source, boost::shared_ptr< afw::image::Exposure< PixelT > const >  parentExposure  )

inline

Construct a PsfCandidate from a specified source and image.

The x/yCenter is set to source.getX/YAstrom()

Parameters

source	The detected Source
parentExposure	The image wherein lie the Sources

Definition at line 76 of file PsfCandidate.h.

          :
            afw::math::SpatialCellMaskedImageCandidate<PixelT>(source->getX(), source->getY()),
            _parentExposure(parentExposure),
            _offsetImage(),
            _source(source),
            _haveImage(false),
            _amplitude(0.0), _var(1.0)
        {}

template<typename PixelT>

lsst::meas::algorithms::PsfCandidate< PixelT >::PsfCandidate ( boost::shared_ptr< afw::table::SourceRecord > const &  source, boost::shared_ptr< afw::image::Exposure< PixelT > const >  parentExposure, double  xCenter, double  yCenter  )

inline

Construct a PsfCandidate from a specified source, image and xyCenter.

Parameters

source	The detected Source
parentExposure	The image wherein lie the Sources
xCenter	the desired x center
yCenter	the desired y center

Definition at line 91 of file PsfCandidate.h.

          :
            afw::math::SpatialCellMaskedImageCandidate<PixelT>(xCenter, yCenter),
            _parentExposure(parentExposure),
            _offsetImage(),
            _source(source),
            _haveImage(false),
            _amplitude(0.0), _var(1.0)
        {}

template<typename PixelT>

virtual lsst::meas::algorithms::PsfCandidate< PixelT >::~PsfCandidate ( )

inlinevirtual

Destructor.

Definition at line 106 of file PsfCandidate.h.

{};

Member Function Documentation

template<typename PixelT >

boost::shared_ptr< afwImage::MaskedImage< PixelT > > lsst::meas::algorithms::PsfCandidate< PixelT >::extractImage ( unsigned int  width, unsigned int  height  ) const

private

Extract an image of the candidate.

The MaskedImage is a deep copy of a sub-image of the original image. No offsets are applied.

In the mask, the INTRP bit is set and DETECTED unset for any pixels that are not considered part of the actual candidate. You should consider that, for the output mask:

• INTRP means "ignore this pixel", i.e., it's contaminated
• DETECTED means "fit this pixel", i.e., it contains the object of interest
• Nothing means "do what you want"

Three schemes are used for masking pixels:

• Pixels closer to a peak in the source footprint other than the central peak are masked. This deals with sources blended with the actual candidate.
• Sources (identified from the DETECTED bit plane) unconnected to the central peak are masked, and this mask is grown. This deals with bright neighbouring sources.
• Pixels exceeding the pixelThreshold relative to the expected noise according to the variance plane are masked if they are not in the central footprint. This is only applied if the pixelThreshold is positive. This deals with faint neighbouring sources.

Definition at line 184 of file PsfCandidate.cc.

        {
    afwGeom::Point2I const cen(afwImage::positionToIndex(getXCenter()),
                               afwImage::positionToIndex(getYCenter()));
    afwGeom::Point2I const llc(cen[0] - width/2 - _parentExposure->getX0(),
                               cen[1] - height/2 - _parentExposure->getY0());

    afwGeom::BoxI bbox(llc, afwGeom::ExtentI(width, height));

    PTR(MaskedImageT) image;
    try {
        MaskedImageT mimg = _parentExposure->getMaskedImage();
        image.reset(new MaskedImageT(mimg, bbox, afwImage::LOCAL, true)); // a deep copy
    } catch(lsst::pex::exceptions::LengthError &e) {
        LSST_EXCEPT_ADD(e, "Extracting image of PSF candidate");
        throw e;
    }

    //
    // Set INTRP and unset DETECTED for any pixels we don't want to deal with.
    //
    afwImage::MaskPixel const intrp = MaskedImageT::Mask::getPlaneBitMask("INTRP"); // mask bit for bad pixels
    afwImage::MaskPixel const detected = MaskedImageT::Mask::getPlaneBitMask("DETECTED"); // object pixels

    // Mask out blended objects
    if (getMaskBlends()) {
        CONST_PTR(afwDetection::Footprint) foot = getSource()->getFootprint();
        typedef afwDetection::PeakCatalog PeakCatalog;
        PeakCatalog const& peaks = foot->getPeaks();
        if (peaks.size() > 1) {
            // Mask all pixels in the footprint except for those closest to the central peak
            double best = std::numeric_limits<double>::infinity();
            PTR(afwDetection::PeakRecord) central;
            for (PeakCatalog::const_iterator iter = peaks.begin(), end = peaks.end(); iter != end; ++iter) {
                double const dist2 = distanceSquared(getXCenter(), getYCenter(), *iter);
                if (dist2 < best) {
                    best = dist2;
                    central = iter;
                }
            }
            assert(central);                // We must have found something

            PeakCatalog others(peaks.getTable());
            others.reserve(peaks.size() - 1);
            for (PeakCatalog::const_iterator iter = peaks.begin(), end = peaks.end(); iter != end; ++iter) {
                PTR(afwDetection::PeakRecord) ptr(iter);
                if (central != ptr) {
                    others.push_back(ptr);
                }
            }

            BlendedFunctor<PixelT> functor(*image, *image->getMask(), *central, others, detected, intrp);
            functor.apply(*foot);
        }
    }

    /*
     * Mask any DETECTED pixels other than the one in the center of the object;
     * we grow the Footprint a bit first
     */
    typedef afwDetection::FootprintSet::FootprintList FootprintList;

    PTR(afwImage::Image<int>) mim = makeImageFromMask<int>(*image->getMask(), makeAndMask(detected));
    PTR(afwDetection::FootprintSet) fs =
        boost::make_shared<afwDetection::FootprintSet>(*mim, afwDetection::Threshold(1));
    CONST_PTR(FootprintList) feet = fs->getFootprints();

    if (feet->size() > 1) {
        int const ngrow = 3;            // number of pixels to grow bad Footprints
        //
        // Go through Footprints looking for ones that don't contain cen
        //
        for (FootprintList::const_iterator fiter = feet->begin(); fiter != feet->end(); ++fiter) {
            PTR(afwDetection::Footprint) foot = *fiter;
            if (foot->contains(cen)) {
                continue;
            }

            PTR(afwDetection::Footprint) bigfoot = afwDetection::growFootprint(foot, ngrow);
            afwDetection::clearMaskFromFootprint(image->getMask().get(), *bigfoot, detected);
            afwDetection::setMaskFromFootprint(image->getMask().get(), *bigfoot, intrp);
        }
    }

    // Mask high pixels unconnected to the center
    if (_pixelThreshold > 0.0) {
        CONST_PTR(afwDetection::FootprintSet) fpSet =
            boost::make_shared<afwDetection::FootprintSet>(*image,
                afwDetection::Threshold(_pixelThreshold, afwDetection::Threshold::PIXEL_STDEV));
        for (FootprintList::const_iterator fpIter = fpSet->getFootprints()->begin();
             fpIter != fpSet->getFootprints()->end(); ++fpIter) {
            CONST_PTR(afwDetection::Footprint) fp = *fpIter;
            if (!fp->contains(cen)) {
                afwDetection::clearMaskFromFootprint(image->getMask().get(), *fp, detected);
                afwDetection::setMaskFromFootprint(image->getMask().get(), *fp, intrp);
            }
        }
    }

    return image;
}

template<typename PixelT>

double lsst::meas::algorithms::PsfCandidate< PixelT >::getAmplitude ( ) const

inline

Return the best-fit amplitude.

Definition at line 119 of file PsfCandidate.h.

{ return _amplitude; }

template<typename PixelT>

static int lsst::meas::algorithms::PsfCandidate< PixelT >::getBorderWidth ( )

inlinestatic

Return the number of pixels being ignored around the candidate image's edge.

Definition at line 136 of file PsfCandidate.h.

{ return _border; }

template<typename PixelT>

double lsst::meas::algorithms::PsfCandidate< PixelT >::getCandidateRating ( ) const

inlinevirtual

Return Cell rating

Note

Required method for use by SpatialCell

Implements lsst::afw::math::SpatialCellCandidate.

Definition at line 113 of file PsfCandidate.h.

{ return _source->getPsfFlux(); }

template<typename PixelT>

static bool lsst::meas::algorithms::PsfCandidate< PixelT >::getMaskBlends ( )

inlinestatic

Get whether blends are masked.

Definition at line 153 of file PsfCandidate.h.

{ return _doMaskBlends; }

template<typename PixelT >

boost::shared_ptr< afwImage::MaskedImage< PixelT > const > lsst::meas::algorithms::PsfCandidate< PixelT >::getMaskedImage ( ) const

virtual

Return the image at the position of the Source, without any sub-pixel shifts to put the centre of the object in the centre of a pixel (for that, use getOffsetImage())

Implements lsst::afw::math::SpatialCellMaskedImageCandidate< PixelT >.

Definition at line 317 of file PsfCandidate.cc.

                                                                                         {

    int const width = getWidth() == 0 ? _defaultWidth : getWidth();
    int const height = getHeight() == 0 ? _defaultWidth : getHeight();

    return getMaskedImage(width, height);

}

template<typename PixelT >

boost::shared_ptr< afwImage::MaskedImage< PixelT > const > lsst::meas::algorithms::PsfCandidate< PixelT >::getMaskedImage	(	int	width,
		int	height
	)		const

Return the image at the position of the Source, without any sub-pixel shifts to put the centre of the object in the centre of a pixel (for that, use getOffsetImage())

Definition at line 296 of file PsfCandidate.cc.

                                                                       {


    if (_haveImage && (width != _image->getWidth() || height != _image->getHeight())) {
        _haveImage = false;
    }

    if (!_haveImage) {
        _image = extractImage(width, height);
        _haveImage = true;
    }

    return _image;
}

template<typename PixelT >

boost::shared_ptr< afwImage::MaskedImage< PixelT > > lsst::meas::algorithms::PsfCandidate< PixelT >::getOffsetImage	(	std::string const	algorithm,
		unsigned int	buffer
	)		const

Return an offset version of the image of the source. The returned image has been offset to put the centre of the object in the centre of a pixel.

Definition at line 333 of file PsfCandidate.cc.

        {
    unsigned int const width = getWidth() == 0 ? _defaultWidth : getWidth();
    unsigned int const height = getHeight() == 0 ? _defaultWidth : getHeight();
    if (_offsetImage && static_cast<unsigned int>(_offsetImage->getWidth()) == width + 2*buffer &&
        static_cast<unsigned int>(_offsetImage->getHeight()) == height + 2*buffer) {
        return _offsetImage;
    }

    PTR(MaskedImageT) image = extractImage(width + 2*buffer, height + 2*buffer);

    double const xcen = getXCenter(), ycen = getYCenter();
    double const dx = afwImage::positionToIndex(xcen, true).second;
    double const dy = afwImage::positionToIndex(ycen, true).second;

    PTR(MaskedImageT) offset = afwMath::offsetImage(*image, -dx, -dy, algorithm);
    afwGeom::Point2I llc(buffer, buffer);
    afwGeom::Extent2I dims(width, height);
    afwGeom::Box2I box(llc, dims);
    _offsetImage.reset(new MaskedImageT(*offset, box, afwImage::LOCAL, true)); // Deep copy

    return _offsetImage;
}

template<typename PixelT>

static float lsst::meas::algorithms::PsfCandidate< PixelT >::getPixelThreshold ( )

inlinestatic

Get threshold for rejecting pixels unconnected with the central footprint.

Definition at line 147 of file PsfCandidate.h.

{ return _pixelThreshold; }

template<typename PixelT>

boost::shared_ptr< afw::table::SourceRecord > lsst::meas::algorithms::PsfCandidate< PixelT >::getSource ( ) const

inline

Return the original Source.

Definition at line 116 of file PsfCandidate.h.

{ return _source; }

template<typename PixelT>

double lsst::meas::algorithms::PsfCandidate< PixelT >::getVar ( ) const

inline

Return the variance in use when fitting this object.

Definition at line 125 of file PsfCandidate.h.

{ return _var; }

template<typename PixelT>

boost::shared_ptr< afw::image::MaskedImage<PixelT> > lsst::meas::algorithms::PsfCandidate< PixelT >::offsetImage ( boost::shared_ptr< afw::image::MaskedImage< PixelT > >  img, std::string const  algorithm, unsigned int  buffer  )

private

template<typename PixelT>

void lsst::meas::algorithms::PsfCandidate< PixelT >::setAmplitude ( double  amplitude )

inline

Set the best-fit amplitude.

Definition at line 122 of file PsfCandidate.h.

{ _amplitude = amplitude; }

template<typename PixelT>

static void lsst::meas::algorithms::PsfCandidate< PixelT >::setBorderWidth ( int  border )

inlinestatic

Set the number of pixels to ignore around the candidate image's edge.

Definition at line 139 of file PsfCandidate.h.

{ _border = border; }

template<typename PixelT>

static void lsst::meas::algorithms::PsfCandidate< PixelT >::setMaskBlends ( bool  doMaskBlends )

inlinestatic

Set whether blends are masked.

Definition at line 150 of file PsfCandidate.h.

{ _doMaskBlends = doMaskBlends; }

template<typename PixelT>

static void lsst::meas::algorithms::PsfCandidate< PixelT >::setPixelThreshold ( float  threshold )

inlinestatic

Set threshold for rejecting pixels unconnected with the central footprint

A non-positive threshold means that no threshold will be applied.

Definition at line 144 of file PsfCandidate.h.

{ _pixelThreshold = threshold; }

template<typename PixelT>

void lsst::meas::algorithms::PsfCandidate< PixelT >::setVar ( double  var )

inline

Set the variance to use when fitting this object.

Definition at line 128 of file PsfCandidate.h.

{ _var = var; }

Member Data Documentation

template<typename PixelT>

double lsst::meas::algorithms::PsfCandidate< PixelT >::_amplitude

private

Definition at line 172 of file PsfCandidate.h.

template<typename PixelT>

int lsst::meas::algorithms::PsfCandidate< PixelT >::_border = 0

staticprivate

Definition at line 174 of file PsfCandidate.h.

template<typename PixelT>

int lsst::meas::algorithms::PsfCandidate< PixelT >::_defaultWidth = 21

staticprivate

Definition at line 176 of file PsfCandidate.h.

template<typename PixelT>

bool lsst::meas::algorithms::PsfCandidate< PixelT >::_doMaskBlends = true

staticprivate

Mask blends when extracting?

Definition at line 178 of file PsfCandidate.h.

template<typename PixelT>

bool lsst::meas::algorithms::PsfCandidate< PixelT >::_haveImage

mutableprivate

Definition at line 171 of file PsfCandidate.h.

template<typename PixelT>

boost::shared_ptr< afw::image::MaskedImage<PixelT> > lsst::meas::algorithms::PsfCandidate< PixelT >::_offsetImage

mutableprivate

Definition at line 168 of file PsfCandidate.h.

template<typename PixelT>

boost::shared_ptr< lsst::afw::image::Exposure<PixelT> const> lsst::meas::algorithms::PsfCandidate< PixelT >::_parentExposure

private

Definition at line 156 of file PsfCandidate.h.

template<typename PixelT>

float lsst::meas::algorithms::PsfCandidate< PixelT >::_pixelThreshold = 0.0

staticprivate

Threshold for masking pixels unconnected with central footprint.

Definition at line 177 of file PsfCandidate.h.

template<typename PixelT>

boost::shared_ptr< afw::table::SourceRecord > lsst::meas::algorithms::PsfCandidate< PixelT >::_source

private

Definition at line 169 of file PsfCandidate.h.

template<typename PixelT>

double lsst::meas::algorithms::PsfCandidate< PixelT >::_var

private

Definition at line 173 of file PsfCandidate.h.

template<typename PixelT>

afw::geom::Point2D lsst::meas::algorithms::PsfCandidate< PixelT >::_xyCenter

private

Definition at line 175 of file PsfCandidate.h.

---

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

• /home/lsstsw/stack/Linux64/meas_algorithms/11.0-2-gb8b8ce7/include/lsst/meas/algorithms/PsfCandidate.h
• /home/lsstsw/stack/Linux64/meas_algorithms/11.0-2-gb8b8ce7/src/PsfCandidate.cc