lsst.meas.base g070148d5b3+002b5a1e24
Loading...
Searching...
No Matches
Public Types | Public Member Functions | Static Public Member Functions | Static Public Attributes | Protected Attributes | List of all members
lsst::meas::base::SdssShapeAlgorithm Class Reference

Measure the image moments of source using adaptive Gaussian weights. More...

#include <SdssShape.h>

Inheritance diagram for lsst::meas::base::SdssShapeAlgorithm:
lsst::meas::base::SimpleAlgorithm lsst::meas::base::SingleFrameAlgorithm lsst::meas::base::ForcedAlgorithm lsst::meas::base::BaseAlgorithm lsst::meas::base::BaseAlgorithm

Public Types

typedef SdssShapeControl Control
 
typedef SdssShapeResult Result
 
typedef SdssShapeResultKey ResultKey
 

Public Member Functions

 SdssShapeAlgorithm (Control const &ctrl, std::string const &name, afw::table::Schema &schema)
 
virtual void measure (afw::table::SourceRecord &measRecord, afw::image::Exposure< float > const &exposure) const
 Called to measure a single child source in an image. More...
 
virtual void fail (afw::table::SourceRecord &measRecord, MeasurementError *error=nullptr) const
 Handle an exception thrown by the current algorithm by setting flags in the given record. More...
 
template<typename ImageT >
SdssShapeResult computeAdaptiveMoments (ImageT const &image, geom::Point2D const &center, bool negative, Control const &control)
 
virtual void measureForced (afw::table::SourceRecord &measRecord, afw::image::Exposure< float > const &exposure, afw::table::SourceRecord const &refRecord, afw::geom::SkyWcs const &refWcs) const
 Called to measure a single child source in an image. More...
 
virtual void measureNForced (afw::table::SourceCatalog const &measCat, afw::image::Exposure< float > const &exposure, afw::table::SourceCatalog const &refRecord, afw::geom::SkyWcs const &refWcs) const
 Called to simultaneously measure all children in a deblend family, in a single image. More...
 
virtual void measureN (afw::table::SourceCatalog const &measCat, afw::image::Exposure< float > const &exposure) const
 Called to simultaneously measure all children in a deblend family, in a single image. More...
 
std::string getLogName () const
 

Static Public Member Functions

static FlagDefinitionList const & getFlagDefinitions ()
 
template<typename ImageT >
static Result computeAdaptiveMoments (ImageT const &image, geom::Point2D const &position, bool negative=false, Control const &ctrl=Control())
 Compute the adaptive Gaussian-weighted moments of an image. More...
 
template<typename ImageT >
static FluxResult computeFixedMomentsFlux (ImageT const &image, afw::geom::ellipses::Quadrupole const &shape, geom::Point2D const &position)
 Compute the instFlux within a fixed Gaussian aperture. More...
 

Static Public Attributes

static unsigned int const N_FLAGS = 6
 
static FlagDefinition const FAILURE = flagDefinitions.addFailureFlag()
 
static FlagDefinition const UNWEIGHTED_BAD
 
static FlagDefinition const UNWEIGHTED
 
static FlagDefinition const SHIFT
 
static FlagDefinition const MAXITER
 
static FlagDefinition const PSF_SHAPE_BAD
 

Protected Attributes

std::string _logName
 

Detailed Description

Measure the image moments of source using adaptive Gaussian weights.

This algorithm measures the weighted second moments of an image using a Gaussian weight function, which is iteratively updated to match the current weights. If this iteration does not converge, it can fall back to using unweighted moments, which can be significantly noisier.

See Bernstein & Jarvis, 2002, for more information on this type of algorithm. Note that the code here makes no attempt to correct for the PSF; for PSF corrected ellipticities using weighted moments please use the shapeHSM package.

Definition at line 150 of file SdssShape.h.

Member Typedef Documentation

◆ Control

Definition at line 162 of file SdssShape.h.

◆ Result

Definition at line 163 of file SdssShape.h.

◆ ResultKey

Definition at line 164 of file SdssShape.h.

Constructor & Destructor Documentation

◆ SdssShapeAlgorithm()

lsst::meas::base::SdssShapeAlgorithm::SdssShapeAlgorithm ( Control const &  ctrl,
std::string const &  name,
afw::table::Schema schema 
)

Definition at line 759 of file SdssShape.cc.

Member Function Documentation

◆ computeAdaptiveMoments() [1/2]

template<typename ImageT >
SdssShapeResult lsst::meas::base::SdssShapeAlgorithm::computeAdaptiveMoments ( ImageT const &  image,
geom::Point2D const &  center,
bool  negative,
Control const &  control 
)

Definition at line 766 of file SdssShape.cc.

◆ computeAdaptiveMoments() [2/2]

template<typename ImageT >
static Result lsst::meas::base::SdssShapeAlgorithm::computeAdaptiveMoments ( ImageT const &  image,
geom::Point2D const &  position,
bool  negative = false,
Control const &  ctrl = Control() 
)
static

Compute the adaptive Gaussian-weighted moments of an image.

Parameters
[in]imageAn Image or MaskedImage instance with int, float, or double pixels. This need not be a small postage stamp (the pixel region actually used in the fit will be a subset of this image determined automatically).
[in]positionCenter position of the object to be measured, in the image's PARENT coordinates.
[in]negativeBoolean, specify if the source is in negative instFlux space
[in]ctrlControl object specifying the details of how the object is to be measured.

◆ computeFixedMomentsFlux()

template<typename ImageT >
template FluxResult lsst::meas::base::SdssShapeAlgorithm::computeFixedMomentsFlux ( ImageT const &  image,
afw::geom::ellipses::Quadrupole const &  shape,
geom::Point2D const &  position 
)
static

Compute the instFlux within a fixed Gaussian aperture.

Parameters
[in]imageAn Image or MaskedImage instance with int, float, or double pixels. This need not be a small postage stamp (the pixel region actually used in the fit will be a subset of this image determined automatically).
[in]shapeEllipse object specifying the 1-sigma contour of the Gaussian.
[in]positionCenter position of the object to be measured, in the image's PARENT coordinates.

Definition at line 834 of file SdssShape.cc.

◆ fail()

void lsst::meas::base::SdssShapeAlgorithm::fail ( afw::table::SourceRecord measRecord,
MeasurementError error = nullptr 
) const
virtual

Handle an exception thrown by the current algorithm by setting flags in the given record.

fail() is called by the measurement framework when an exception is allowed to propagate out of one the algorithm's measure() methods. It should generally set both a general failure flag for the algorithm as well as a specific flag indicating the error condition, if possible. To aid in this, if the exception was an instance of MeasurementError, it will be passed in, carrying information about what flag to set.

An algorithm can also to chose to set flags within its own measure() methods, and then just return, rather than throw an exception. However, fail() should be implemented even when all known failure modes do not throw exceptions, to ensure that unexpected exceptions thrown in lower-level code are properly handled.

Implements lsst::meas::base::BaseAlgorithm.

Definition at line 916 of file SdssShape.cc.

◆ getFlagDefinitions()

FlagDefinitionList const & lsst::meas::base::SdssShapeAlgorithm::getFlagDefinitions ( )
static

Definition at line 58 of file SdssShape.cc.

◆ getLogName()

std::string lsst::meas::base::BaseAlgorithm::getLogName ( ) const
inlineinherited

Definition at line 66 of file Algorithm.h.

◆ measure()

void lsst::meas::base::SdssShapeAlgorithm::measure ( afw::table::SourceRecord measRecord,
afw::image::Exposure< float > const &  exposure 
) const
virtual

Called to measure a single child source in an image.

Before this method is called, all neighbors will be replaced with noise, using the outputs of the deblender. Outputs should be saved in the given SourceRecord, which can also be used to obtain centroid (see SafeCentroidExtractor) and shape (see SafeShapeExtractor) information.

Implements lsst::meas::base::SingleFrameAlgorithm.

Definition at line 881 of file SdssShape.cc.

◆ measureForced()

virtual void lsst::meas::base::SimpleAlgorithm::measureForced ( afw::table::SourceRecord measRecord,
afw::image::Exposure< float > const &  exposure,
afw::table::SourceRecord const &  refRecord,
afw::geom::SkyWcs const &  refWcs 
) const
inlinevirtualinherited

Called to measure a single child source in an image.

Before this method is called, all neighbors will be replaced with noise, using the outputs of the deblender. Outputs should be saved in the given SourceRecord, which can also be used to obtain centroid (see SafeCentroidExtractor) and shape (see SafeShapeExtractor) information.

Implements lsst::meas::base::ForcedAlgorithm.

Definition at line 172 of file Algorithm.h.

◆ measureN()

void lsst::meas::base::SingleFrameAlgorithm::measureN ( afw::table::SourceCatalog const &  measCat,
afw::image::Exposure< float > const &  exposure 
) const
virtualinherited

Called to simultaneously measure all children in a deblend family, in a single image.

Outputs should be saved in the given SourceCatalog, which can also be used to obtain centroid (see SafeCentroidExtractor) and shape (see SafeShapeExtractor) information.

The default implementation simply throws an exception, indicating that simultaneous measurement is not supported.

Definition at line 31 of file Algorithm.cc.

◆ measureNForced()

virtual void lsst::meas::base::SimpleAlgorithm::measureNForced ( afw::table::SourceCatalog const &  measCat,
afw::image::Exposure< float > const &  exposure,
afw::table::SourceCatalog const &  refRecord,
afw::geom::SkyWcs const &  refWcs 
) const
inlinevirtualinherited

Called to simultaneously measure all children in a deblend family, in a single image.

Outputs should be saved in the given SourceCatalog, which can also be used to obtain centroid (see SafeCentroidExtractor) and shape (see SafeShapeExtractor) information.

The default implementation simply throws an exception, indicating that simultaneous measurement is not supported.

Reimplemented from lsst::meas::base::ForcedAlgorithm.

Definition at line 179 of file Algorithm.h.

Member Data Documentation

◆ _logName

std::string lsst::meas::base::BaseAlgorithm::_logName
protectedinherited

Definition at line 69 of file Algorithm.h.

◆ FAILURE

FlagDefinition const lsst::meas::base::SdssShapeAlgorithm::FAILURE = flagDefinitions.addFailureFlag()
static

Definition at line 155 of file SdssShape.h.

◆ MAXITER

FlagDefinition const lsst::meas::base::SdssShapeAlgorithm::MAXITER
static
Initial value:
=
flagDefinitions.add("flag_maxIter", "Too many iterations in adaptive moments")

Definition at line 159 of file SdssShape.h.

◆ N_FLAGS

unsigned int const lsst::meas::base::SdssShapeAlgorithm::N_FLAGS = 6
static

Definition at line 154 of file SdssShape.h.

◆ PSF_SHAPE_BAD

FlagDefinition const lsst::meas::base::SdssShapeAlgorithm::PSF_SHAPE_BAD
static
Initial value:
=
flagDefinitions.add("flag_psf", "Failure in measuring PSF model shape")

Definition at line 160 of file SdssShape.h.

◆ SHIFT

FlagDefinition const lsst::meas::base::SdssShapeAlgorithm::SHIFT
static
Initial value:
=
flagDefinitions.add("flag_shift", "centroid shifted by more than the maximum allowed amount")

Definition at line 158 of file SdssShape.h.

◆ UNWEIGHTED

FlagDefinition const lsst::meas::base::SdssShapeAlgorithm::UNWEIGHTED
static
Initial value:
= flagDefinitions.add(
"flag_unweighted", "Weighted moments converged to an invalid value; using unweighted moments")

Definition at line 157 of file SdssShape.h.

◆ UNWEIGHTED_BAD

FlagDefinition const lsst::meas::base::SdssShapeAlgorithm::UNWEIGHTED_BAD
static
Initial value:
=
flagDefinitions.add("flag_unweightedBad", "Both weighted and unweighted moments were invalid")

Definition at line 156 of file SdssShape.h.


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