File Threshold.h

namespace lsst

Class for a simple mapping implementing a generic AstrometryTransform.

Remove all non-astronomical counts from the Chunk Exposure’s pixels.

Forward declarations for lsst::utils::Cache

For details on the Cache class, see the Cache.h file.

It uses a template rather than a pointer so that the derived classes can use the specifics of the transform. The class simplePolyMapping overloads a few routines.

A base class for image defects

Numeric constants used by the Integrate.h integrator routines.

Compute Image Statistics

Note

Gauss-Kronrod-Patterson quadrature coefficients for use in quadpack routine qng. These coefficients were calculated with 101 decimal digit arithmetic by L. W. Fullerton, Bell Labs, Nov 1981.

Note

The Statistics class itself can only handle lsst::afw::image::MaskedImage() types. The philosophy has been to handle other types by making them look like lsst::afw::image::MaskedImage() and reusing that code. Users should have no need to instantiate a Statistics object directly, but should use the overloaded makeStatistics() factory functions.

namespace afw
namespace detection

Functions

Threshold createThreshold(const double value, const std::string type = "value", const bool polarity = true)

Factory method for creating Threshold objects

Return

desired Threshold

Parameters

  • value: value of threshold

  • type: string representation of a ThresholdType. This parameter is optional. Allowed values are: “variance”, “value”, “stdev”, “pixel_stdev”

  • polarity: If true detect positive objects, false for negative

class Threshold
#include <Threshold.h>

A Threshold is used to pass a threshold value to detection algorithms

The threshold may be a simple value (type == VALUE), or in units of the image standard deviation. Alternatively you may specify that you’ll provide the standard deviation (type == STDEV) or variance (type == VARIANCE)

Note that the constructor is not declared explicit, so you may pass a bare threshold, and it’ll be interpreted as a VALUE.

Public Types

enum ThresholdType

Types of threshold:

Values:

VALUE

Use pixel value.

BITMASK

Use (pixels & (given mask))

STDEV

Use number of sigma given s.d.

VARIANCE

Use number of sigma given variance.

PIXEL_STDEV

Use number of sigma given per-pixel s.d.

Public Functions

Threshold(double const value, ThresholdType const type = VALUE, bool const polarity = true, double const includeMultiplier = 1.0)

Parameters

  • value: desired threshold value

  • type: interpretation of type

  • polarity: search pixel above threshold? (useful for -ve thresholds)

  • includeMultiplier: threshold multiplier for inclusion in FootprintSet

Threshold constructor

~Threshold()
Threshold(Threshold const&)
Threshold(Threshold&&)
Threshold &operator=(Threshold const&)
Threshold &operator=(Threshold&&)
ThresholdType getType() const

return type of threshold

double getValue(const double param = -1) const

return value of threshold, to be interpreted via type

Return

value of threshold

Parameters

  • param: value of variance/stdev if needed

template<typename ImageT>
double getValue(ImageT const &image) const

return value of threshold by interrogating the image, if required

Return

value of threshold

Parameters

  • image: Image to interrogate, if threshold type demands

bool getPolarity() const

return Threshold’s polarity

void setPolarity(bool const polarity)

set Threshold’s polarity

Parameters

  • polarity: desired polarity

double getIncludeMultiplier() const

return includeMultiplier

void setIncludeMultiplier(double const includeMultiplier)

set includeMultiplier

Parameters

  • includeMultiplier: desired multiplier

Public Static Functions

static ThresholdType parseTypeString(std::string const &typeStr)
static std::string getTypeString(ThresholdType const &type)

Private Members

double _value

value of threshold, to be interpreted via _type

ThresholdType _type

type of threshold

bool _polarity

true for positive polarity, false for negative

double _includeMultiplier

multiplier for threshold needed for inclusion in FootprintSet