lsst::meas::algorithms::WarpedPsf Class Reference

A Psf class that maps an arbitrary Psf through a coordinate transformation. More...

#include <WarpedPsf.h>

Inheritance diagram for lsst::meas::algorithms::WarpedPsf:

Public Member Functions
	WarpedPsf (boost::shared_ptr< afw::detection::Psf const > undistortedPsf, boost::shared_ptr< afw::geom::XYTransform const > distortion, boost::shared_ptr< afw::math::WarpingControl const > control)
	Construct WarpedPsf from unwarped psf and distortion. More...
	WarpedPsf (boost::shared_ptr< afw::detection::Psf const > undistortedPsf, boost::shared_ptr< afw::geom::XYTransform const > distortion, std::string const &kernelName="lanczos3", unsigned int cache=10000)
virtual afw::geom::Point2D	getAveragePosition () const
	Return the average of the positions of the stars that went into this Psf. More...
virtual boost::shared_ptr < afw::detection::Psf >	clone () const
	Polymorphic deep copy. Usually unnecessary, as Psfs are immutable. More...
Public Member Functions inherited from lsst::afw::detection::Psf
virtual	~Psf ()
boost::shared_ptr< Image >	computeImage (geom::Point2D position=makeNullPoint(), image::Color color=image::Color(), ImageOwnerEnum owner=COPY) const
	Return an Image of the PSF, in a form that can be compared directly with star images. More...
boost::shared_ptr< Image >	computeKernelImage (geom::Point2D position=makeNullPoint(), image::Color color=image::Color(), ImageOwnerEnum owner=COPY) const
	Return an Image of the PSF, in a form suitable for convolution. More...
double	computePeak (geom::Point2D position=makeNullPoint(), image::Color color=image::Color()) const
	Return the peak value of the PSF image. More...
double	computeApertureFlux (double radius, geom::Point2D position=makeNullPoint(), image::Color color=image::Color()) const
	Compute the "flux" of the Psf model within a circular aperture of the given radius. More...
geom::ellipses::Quadrupole	computeShape (geom::Point2D position=makeNullPoint(), image::Color color=image::Color()) const
	Compute the ellipse corresponding to the second moments of the Psf. More...
boost::shared_ptr < math::Kernel const >	getLocalKernel (geom::Point2D position=makeNullPoint(), image::Color color=image::Color()) const
	Return a FixedKernel corresponding to the Psf image at the given point. More...
image::Color	getAverageColor () const
	Return the average Color of the stars used to construct the Psf. More...
Public Member Functions inherited from lsst::daf::base::Citizen
	Citizen (const std::type_info &)
	Citizen (Citizen const &)
	~Citizen ()
Citizen &	operator= (Citizen const &)
std::string	repr () const
	Return a string representation of a Citizen. More...
void	markPersistent (void)
	Mark a Citizen as persistent and not destroyed until process end. More...
memId	getId () const
	Return the Citizen's ID. More...
Public Member Functions inherited from lsst::daf::base::Persistable
	Persistable (void)
virtual	~Persistable (void)
template<class Archive >
void	serialize (Archive &, unsigned int const)
Public Member Functions inherited from lsst::afw::table::io::Persistable
void	writeFits (std::string const &fileName, std::string const &mode="w") const
	Write the object to a regular FITS file. More...
void	writeFits (fits::MemFileManager &manager, std::string const &mode="w") const
	Write the object to a FITS image in memory. More...
void	writeFits (fits::Fits &fitsfile) const
	Write the object to an already-open FITS object. More...
virtual bool	isPersistable () const
	Return true if this particular object can be persisted using afw::table::io. More...
virtual	~Persistable ()

Protected Member Functions
virtual boost::shared_ptr < afw::detection::Psf::Image >	doComputeKernelImage (afw::geom::Point2D const &position, afw::image::Color const &color) const
Protected Member Functions inherited from lsst::meas::algorithms::ImagePsf
	ImagePsf (bool isFixed=false)
virtual double	doComputeApertureFlux (double radius, afw::geom::Point2D const &position, afw::image::Color const &color) const
virtual afw::geom::ellipses::Quadrupole	doComputeShape (afw::geom::Point2D const &position, afw::image::Color const &color) const
Protected Member Functions inherited from lsst::afw::detection::Psf
	Psf (bool isFixed=false)
Protected Member Functions inherited from lsst::afw::table::io::Persistable
virtual std::string	getPersistenceName () const
	Return the unique name used to persist this object and look up its factory. More...
virtual std::string	getPythonModule () const
	Return the fully-qualified Python module that should be imported to guarantee that its factory is registered. More...
virtual void	write (OutputArchiveHandle &handle) const
	Write the object to one or more catalogs. More...
	Persistable ()
	Persistable (Persistable const &other)
void	operator= (Persistable const &other)

Protected Attributes
boost::shared_ptr < afw::detection::Psf const >	_undistortedPsf
boost::shared_ptr < afw::geom::XYTransform const >	_distortion

Private Member Functions
void	_init ()

Private Attributes
boost::shared_ptr < afw::math::WarpingControl const >	_warpingControl

Additional Inherited Members
Public Types inherited from lsst::afw::detection::Psf
enum	ImageOwnerEnum { COPY =0, INTERNAL =1 }
	Enum passed to computeImage and computeKernelImage to determine image ownership. More...
typedef boost::shared_ptr< Psf >	Ptr
typedef boost::shared_ptr < const Psf >	ConstPtr
typedef math::Kernel::Pixel	Pixel
	Pixel type of Image returned by computeImage. More...
typedef image::Image< Pixel >	Image
	Image type returned by computeImage. More...
Public Types inherited from lsst::daf::base::Citizen
enum	{ magicSentinel = 0xdeadbeef }
typedef unsigned long	memId
	Type of the block's ID. More...
typedef memId(*	memNewCallback )(const memId cid)
	A function used to register a callback. More...
typedef memId(*	memCallback )(const Citizen *ptr)
Public Types inherited from lsst::daf::base::Persistable
typedef boost::shared_ptr < Persistable >	Ptr
Static Public Member Functions inherited from lsst::afw::table::io::PersistableFacade< ImagePsf >
static boost::shared_ptr < ImagePsf >	readFits (fits::Fits &fitsfile)
	Read an object from an already open FITS object. More...
static boost::shared_ptr < ImagePsf >	readFits (std::string const &fileName, int hdu=0)
	Read an object from a regular FITS file. More...
static boost::shared_ptr < ImagePsf >	readFits (fits::MemFileManager &manager, int hdu=0)
	Read an object from a FITS file in memory. More...
Static Public Member Functions inherited from lsst::afw::detection::Psf
static boost::shared_ptr< Image >	recenterKernelImage (boost::shared_ptr< Image > im, geom::Point2D const &position, std::string const &warpAlgorithm="lanczos5", unsigned int warpBuffer=5)
Static Public Member Functions inherited from lsst::daf::base::Citizen
static bool	hasBeenCorrupted ()
	Check all allocated blocks for corruption. More...
static memId	getNextMemId ()
	Return the memId of the next object to be allocated. More...
static int	init ()
	Called once when the memory system is being initialised. More...
static int	census (int, memId startingMemId=0)
	How many active Citizens are there? More...
static void	census (std::ostream &stream, memId startingMemId=0)
	Print a list of all active Citizens to stream, sorted by ID. More...
static const std::vector < const Citizen * > *	census ()
	Return a (newly allocated) std::vector of active Citizens sorted by ID. More...
static memId	setNewCallbackId (memId id)
	Call the NewCallback when block is allocated. More...
static memId	setDeleteCallbackId (memId id)
	Call the current DeleteCallback when block is deleted. More...
static memNewCallback	setNewCallback (memNewCallback func)
	Set the NewCallback function. More...
static memCallback	setDeleteCallback (memCallback func)
	Set the DeleteCallback function. More...
static memCallback	setCorruptionCallback (memCallback func)
	Set the CorruptionCallback function. More...
Static Public Member Functions inherited from lsst::afw::table::io::PersistableFacade< Psf >
static boost::shared_ptr< Psf >	readFits (fits::Fits &fitsfile)
	Read an object from an already open FITS object. More...
static boost::shared_ptr< Psf >	readFits (std::string const &fileName, int hdu=0)
	Read an object from a regular FITS file. More...
static boost::shared_ptr< Psf >	readFits (fits::MemFileManager &manager, int hdu=0)
	Read an object from a FITS file in memory. More...
Protected Types inherited from lsst::afw::table::io::Persistable
typedef io::OutputArchiveHandle	OutputArchiveHandle

Detailed Description

A Psf class that maps an arbitrary Psf through a coordinate transformation.

If K_0(x,x') is the unwarped PSF, and f is the coordinate transform, then the warped PSF is defined by

K(f(x),f(x')) = K_0(x,x') (*)

We linearize the coordinate transform in the vicinity of the point where the PSF is computed. The definition (*) does not include the Jacobian of the transformation, since the afw convention is that PSF's are normalized to have integral 1 anyway.

Definition at line 49 of file WarpedPsf.h.

Constructor & Destructor Documentation

lsst::meas::algorithms::WarpedPsf::WarpedPsf	(	boost::shared_ptr< afw::detection::Psf const >	undistortedPsf,
		boost::shared_ptr< afw::geom::XYTransform const >	distortion,
		boost::shared_ptr< afw::math::WarpingControl const >	control
	)

Construct WarpedPsf from unwarped psf and distortion.

If p is the nominal pixel position, and p' is the true position on the sky, then our convention for the transform is that p' = distortion.forwardTransform(p)

Definition at line 128 of file WarpedPsf.cc.

      :
    ImagePsf(false),
    _undistortedPsf(undistortedPsf),
    _distortion(distortion),
    _warpingControl(control)
{
    _init();
}

lsst::meas::algorithms::WarpedPsf::WarpedPsf	(	boost::shared_ptr< afw::detection::Psf const >	undistortedPsf,
		boost::shared_ptr< afw::geom::XYTransform const >	distortion,
		std::string const &	kernelName = "lanczos3",
		unsigned int	cache = 10000
	)

Definition at line 141 of file WarpedPsf.cc.

      :
    ImagePsf(false),
    _undistortedPsf(undistortedPsf),
    _distortion(distortion),
    _warpingControl(new afw::math::WarpingControl(kernelName, "", cache))
{
    _init();
}

Member Function Documentation

void lsst::meas::algorithms::WarpedPsf::_init ( )

private

Definition at line 155 of file WarpedPsf.cc.

{
    if (!_undistortedPsf) {
        throw LSST_EXCEPT(
            pex::exceptions::LogicError,
            "Undistorted Psf passed to WarpedPsf must not be None/NULL"
        );
    }
    if (!_distortion) {
        throw LSST_EXCEPT(
            pex::exceptions::LogicError,
            "XYTransform passed to WarpedPsf must not be None/NULL"
        );
    }
    if (!_warpingControl) {
        throw LSST_EXCEPT(
            pex::exceptions::LogicError,
            "WarpingControl passed to WarpedPsf must not be None/NULL"
        );
    }
}

boost::shared_ptr< afw::detection::Psf > lsst::meas::algorithms::WarpedPsf::clone ( void  ) const

virtual

Polymorphic deep copy. Usually unnecessary, as Psfs are immutable.

Implements lsst::afw::detection::Psf.

Definition at line 181 of file WarpedPsf.cc.

                                            {
    return boost::make_shared<WarpedPsf>(_undistortedPsf->clone(), _distortion->clone(), _warpingControl);
}

boost::shared_ptr< afw::detection::Psf::Image > lsst::meas::algorithms::WarpedPsf::doComputeKernelImage ( afw::geom::Point2D const &  position, afw::image::Color const &  color  ) const

protectedvirtual

These virtual member functions are private, not protected, because we only want derived classes to implement them, not call them; they should call the corresponding compute*Image member functions instead so as to let the Psf base class handle caching properly.

Derived classes are responsible for ensuring that returned images sum to one.

Implements lsst::afw::detection::Psf.

Definition at line 185 of file WarpedPsf.cc.

        {
    afw::geom::AffineTransform t = _distortion->linearizeReverseTransform(position);
    afw::geom::Point2D tp = t(position);

    PTR(Image) im = _undistortedPsf->computeKernelImage(tp, color);

    // Go to the warped coordinate system with 'p' at the origin
    PTR(afw::detection::Psf::Psf::Image) ret
        = warpAffine(*im, afw::geom::AffineTransform(t.invert().getLinear()), *_warpingControl);

    double normFactor = 1.0;
    // 
    // Normalize the output image to sum 1
    // FIXME defining a member function Image::getSum() would be convenient here and in other places
    //
    normFactor = 0.0;
    for (int y = 0; y != ret->getHeight(); ++y) {
        afw::detection::Psf::Image::x_iterator imEnd = ret->row_end(y);
        for (afw::detection::Psf::Image::x_iterator imPtr = ret->row_begin(y); imPtr != imEnd; imPtr++) {
            normFactor += *imPtr;
        }
    }
    if (normFactor == 0.0) {
        throw LSST_EXCEPT(pex::exceptions::InvalidParameterError, "psf image has sum 0");
    }
    *ret /= normFactor;
    return ret;
}

afw::geom::Point2D lsst::meas::algorithms::WarpedPsf::getAveragePosition ( ) const

virtual

Return the average of the positions of the stars that went into this Psf.

For WarpedPsf, this is just the transform of the undistorted Psf's average position.

Reimplemented from lsst::afw::detection::Psf.

Definition at line 177 of file WarpedPsf.cc.

                                                   {
    return _distortion->forwardTransform(_undistortedPsf->getAveragePosition());
}

Member Data Documentation

boost::shared_ptr< afw::geom::XYTransform const > lsst::meas::algorithms::WarpedPsf::_distortion

protected

Definition at line 88 of file WarpedPsf.h.

boost::shared_ptr< afw::detection::Psf const > lsst::meas::algorithms::WarpedPsf::_undistortedPsf

protected

Definition at line 87 of file WarpedPsf.h.

boost::shared_ptr< afw::math::WarpingControl const> lsst::meas::algorithms::WarpedPsf::_warpingControl

private

Definition at line 92 of file WarpedPsf.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/WarpedPsf.h
• /home/lsstsw/stack/Linux64/meas_algorithms/11.0-2-gb8b8ce7/src/WarpedPsf.cc