lsst::meas::extensions::photometryKron::KronAperture Class Reference

#include <photometryKron.h>

Public Member Functions
	KronAperture (geom::Point2D const &center, afw::geom::ellipses::BaseCore const &core, float radiusForRadius=std::nanf(""))
	KronAperture (afw::table::SourceRecord const &source, float radiusForRadius=std::nanf(""))
	KronAperture (afw::table::SourceRecord const &reference, geom::AffineTransform const &refToMeas, double radius, float radiusForRadius=std::nanf(""))
double	getX () const
	Accessors. More...
double	getY () const
float	getRadiusForRadius () const
geom::Point2D const &	getCenter () const
afw::geom::ellipses::Axes &	getAxes ()
afw::geom::ellipses::Axes const &	getAxes () const
template<typename ImageT >
std::pair< double, double >	measureFlux (ImageT const &image, double const nRadiusForFlux, double const maxSincRadius) const
	Photometer within the Kron Aperture on an image. More...
std::shared_ptr< KronAperture >	transform (geom::AffineTransform const &trans) const
	Transform a Kron Aperture to a different frame. More...

Static Public Member Functions
template<typename ImageT >
static std::shared_ptr< KronAperture >	determineRadius (ImageT const &image, afw::geom::ellipses::Axes axes, geom::Point2D const &center, KronFluxControl const &ctrl)
	Determine the Kron Aperture from an image. More...
static afw::geom::ellipses::Axes	getKronAxes (afw::geom::ellipses::Axes const &shape, geom::LinearTransform const &transformation, double const radius)
	Determine Kron axes from a reference image. More...

Detailed Description

Definition at line 160 of file photometryKron.h.

Constructor & Destructor Documentation

KronAperture() [1/3]

lsst::meas::extensions::photometryKron::KronAperture::KronAperture ( geom::Point2D const &  center, afw::geom::ellipses::BaseCore const &  core, float  radiusForRadius = std::nanf("")  )

inline

Definition at line 162 of file photometryKron.h.

                                                    :
        _center(center),
        _axes(core),
        _radiusForRadius(radiusForRadius)
        {}

KronAperture() [2/3]

lsst::meas::extensions::photometryKron::KronAperture::KronAperture ( afw::table::SourceRecord const &  source, float  radiusForRadius = std::nanf("")  )

inlineexplicit

Definition at line 169 of file photometryKron.h.

                                                                                                 :
        _center(geom::Point2D(source.getX(), source.getY())),
        _axes(source.getShape()),
        _radiusForRadius(radiusForRadius)
        {}

KronAperture() [3/3]

lsst::meas::extensions::photometryKron::KronAperture::KronAperture ( afw::table::SourceRecord const &  reference, geom::AffineTransform const &  refToMeas, double  radius, float  radiusForRadius = std::nanf("")  )

inline

Definition at line 175 of file photometryKron.h.

                                                                   :
        _center(refToMeas(reference.getCentroid())),
        _axes(getKronAxes(reference.getShape(), refToMeas.getLinear(), radius)),
        _radiusForRadius(radiusForRadius)
        {}

Member Function Documentation

determineRadius()

template<typename ImageT >

std::shared_ptr< KronAperture > lsst::meas::extensions::photometryKron::KronAperture::determineRadius ( ImageT const &  image, afw::geom::ellipses::Axes  axes, geom::Point2D const &  center, KronFluxControl const &  ctrl  )

static

Determine the Kron Aperture from an image.

Determines the object Kron aperture, using the shape from source.getShape() (e.g. SDSS's adaptive moments)

Parameters

image	Image to measure
axes	Shape of aperture
center	Centre of source
ctrl	control the algorithm

Definition at line 234 of file KronPhotometry.cc.

{
    //
    // We might smooth the image because this is what SExtractor and Pan-STARRS do.  But I don't see much gain
    //
    double const sigma = ctrl.smoothingSigma; // Gaussian width of smoothing sigma to apply
    bool const smoothImage = sigma > 0;
    int kSize = smoothImage ? 2*int(2*sigma) + 1 : 1;
    afw::math::GaussianFunction1<afw::math::Kernel::Pixel> gaussFunc(smoothImage ? sigma : 100);
    afw::math::SeparableKernel kernel(kSize, kSize, gaussFunc, gaussFunc);
    bool const doNormalize = true, doCopyEdge = false;
    afw::math::ConvolutionControl convCtrl(doNormalize, doCopyEdge);
    double radius0 = axes.getDeterminantRadius();
    double radius = std::numeric_limits<double>::quiet_NaN();
    float radiusForRadius = std::nanf("");
    for (int i = 0; i < ctrl.nIterForRadius; ++i) {
        axes.scale(ctrl.nSigmaForRadius);
        radiusForRadius = axes.getDeterminantRadius(); // radius we used to estimate R_K
        //
        // Build an elliptical Footprint of the proper size
        //
        afw::detection::Footprint foot(afw::geom::SpanSet::fromShape(
            afw::geom::ellipses::Ellipse(axes, center)));
        geom::Box2I bbox = !smoothImage ?
            foot.getBBox() :
            kernel.growBBox(foot.getBBox()); // the smallest bbox needed to convolve with Kernel
        bbox.clip(image.getBBox());
        ImageT subImage(image, bbox, afw::image::PARENT, smoothImage);
        if (smoothImage) {
            afw::math::convolve(subImage, ImageT(image, bbox, afw::image::PARENT, false), kernel, convCtrl);
        }
        //
        // Find the desired first moment of the elliptical radius, which corresponds to the major axis.
        //
        FootprintFindMoment<ImageT, afw::detection::Psf::Image> iRFunctor(
            subImage, center, axes.getA()/axes.getB(), axes.getTheta()
        );
 
        try {
            foot.getSpans()->applyFunctor(
                iRFunctor, *(subImage.getImage()));
        } catch(lsst::pex::exceptions::OutOfRangeError &e) {
            if (i == 0) {
                LSST_EXCEPT_ADD(e, "Determining Kron aperture");
            }
            break;                      // use the radius we have
        }
 
        if (!iRFunctor.getGood()) {
            throw LSST_EXCEPT(BadKronException, "Bad integral defining Kron radius");
        }
 
        radius = iRFunctor.getIr()*sqrt(axes.getB()/axes.getA());
        if (radius <= radius0) {
            break;
        }
        radius0 = radius;
 
        axes.scale(radius/axes.getDeterminantRadius()); // set axes to our current estimate of R_K
        iRFunctor.reset();
    }
 
    return std::make_shared<KronAperture>(center, axes, radiusForRadius);
}

getAxes() [1/2]

afw::geom::ellipses::Axes & lsst::meas::extensions::photometryKron::KronAperture::getAxes ( )

inline

Definition at line 189 of file photometryKron.h.

{ return _axes; }

getAxes() [2/2]

afw::geom::ellipses::Axes const & lsst::meas::extensions::photometryKron::KronAperture::getAxes ( ) const

inline

Definition at line 191 of file photometryKron.h.

{ return _axes; }

getCenter()

geom::Point2D const & lsst::meas::extensions::photometryKron::KronAperture::getCenter ( ) const

inline

Definition at line 187 of file photometryKron.h.

{ return _center; }

getKronAxes()

afw::geom::ellipses::Axes lsst::meas::extensions::photometryKron::KronAperture::getKronAxes ( afw::geom::ellipses::Axes const &  shape, geom::LinearTransform const &  transformation, double const  radius  )

static

Determine Kron axes from a reference image.

Definition at line 222 of file KronPhotometry.cc.

{
    afw::geom::ellipses::Axes axes(shape);
    axes.scale(radius/axes.getDeterminantRadius());
    return axes.transform(transformation);
}

getRadiusForRadius()

float lsst::meas::extensions::photometryKron::KronAperture::getRadiusForRadius ( ) const

inline

Definition at line 185 of file photometryKron.h.

{ return _radiusForRadius; }

getX()

double lsst::meas::extensions::photometryKron::KronAperture::getX ( ) const

inline

Accessors.

Definition at line 183 of file photometryKron.h.

{ return _center.getX(); }

getY()

double lsst::meas::extensions::photometryKron::KronAperture::getY ( ) const

inline

Definition at line 184 of file photometryKron.h.

{ return _center.getY(); }

measureFlux()

template<typename ImageT >

std::pair< double, double > lsst::meas::extensions::photometryKron::KronAperture::measureFlux	(	ImageT const &	image,
		double const	nRadiusForFlux,
		double const	maxSincRadius
	)		const

Photometer within the Kron Aperture on an image.

Parameters

image	Image to measure
nRadiusForFlux	Kron radius multiplier
maxSincRadius	largest radius that we use sinc apertyres

Definition at line 346 of file KronPhotometry.cc.

{
    afw::geom::ellipses::Axes axes(getAxes()); // Copy of ellipse core, so we can scale
    axes.scale(nRadiusForFlux);
    afw::geom::ellipses::Ellipse const ellip(axes, getCenter());
 
    return photometer(image, ellip, maxSincRadius);
}

transform()

std::shared_ptr< KronAperture > lsst::meas::extensions::photometryKron::KronAperture::transform ( geom::AffineTransform const &  trans ) const

inline

Transform a Kron Aperture to a different frame.

Definition at line 215 of file photometryKron.h.

                                                                                  {
        geom::Point2D const center = trans(getCenter());
        afw::geom::ellipses::Axes const axes(*getAxes().transform(trans.getLinear()).copy());
        return std::make_shared<KronAperture>(center, axes);
    }

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

• /j/snowflake/release/lsstsw/stack/lsst-scipipe-4.0.1/Linux64/meas_extensions_photometryKron/g7271f0639c+98f8679e14/include/lsst/meas/extensions/photometryKron.h
• /j/snowflake/release/lsstsw/stack/lsst-scipipe-4.0.1/Linux64/meas_extensions_photometryKron/g7271f0639c+98f8679e14/src/KronPhotometry.cc