lsst::ip::diffim::ImageStatistics< PixelT > Class Template Reference

Class to calculate difference image statistics. More...

#include <ImageStatistics.h>

Public Types
typedef std::shared_ptr< ImageStatistics >	Ptr
typedef lsst::afw::image::MaskedImage< PixelT >::x_iterator	x_iterator

Public Member Functions
	ImageStatistics (lsst::pex::policy::Policy const &policy)
virtual	~ImageStatistics ()
void	reset ()
void	apply (lsst::afw::image::MaskedImage< PixelT > const &image)
void	apply (lsst::afw::image::MaskedImage< PixelT > const &image, int core)
void	setBpMask (lsst::afw::image::MaskPixel bpMask)
lsst::afw::image::MaskPixel	getBpMask ()
double	getMean () const
double	getVariance () const
double	getRms () const
int	getNpix () const
bool	evaluateQuality (lsst::pex::policy::Policy const &policy)

Detailed Description

template<typename PixelT>
class lsst::ip::diffim::ImageStatistics< PixelT >

Class to calculate difference image statistics.

Note

Find mean and unbiased variance of pixel residuals in units of sqrt(variance)

Definition at line 59 of file ImageStatistics.h.

Member Typedef Documentation

Ptr

template<typename PixelT>

typedef std::shared_ptr<ImageStatistics> lsst::ip::diffim::ImageStatistics< PixelT >::Ptr

Definition at line 61 of file ImageStatistics.h.

x_iterator

template<typename PixelT>

typedef lsst::afw::image::MaskedImage<PixelT>::x_iterator lsst::ip::diffim::ImageStatistics< PixelT >::x_iterator

Definition at line 62 of file ImageStatistics.h.

Constructor & Destructor Documentation

ImageStatistics()

template<typename PixelT>

lsst::ip::diffim::ImageStatistics< PixelT >::ImageStatistics ( lsst::pex::policy::Policy const &  policy )

inline

Definition at line 64 of file ImageStatistics.h.

                                                           : 
        _xsum(0.), _x2sum(0.), _npix(0), _bpMask(0) {
            
            std::vector<std::string> detBadMaskPlanes = policy.getStringArray("badMaskPlanes");
            for (std::vector<std::string>::iterator mi = detBadMaskPlanes.begin();
                 mi != detBadMaskPlanes.end(); ++mi){

                try {
                    _bpMask |= lsst::afw::image::Mask<lsst::afw::image::MaskPixel>::getPlaneBitMask(*mi);
                } catch (pexExcept::Exception& e) {
                    LOGL_DEBUG("TRACE4.ip.diffim.ImageStatistics",
                               "Cannot update bad bit mask with %s", (*mi).c_str());
                    LOGL_DEBUG("TRACE5.ip.diffim.ImageStatistics",
                               e.what());
                }
            }
        } ;

~ImageStatistics()

template<typename PixelT>

virtual lsst::ip::diffim::ImageStatistics< PixelT >::~ImageStatistics ( )

inlinevirtual

Definition at line 81 of file ImageStatistics.h.

{} ;

Member Function Documentation

apply() [1/2]

template<typename PixelT>

void lsst::ip::diffim::ImageStatistics< PixelT >::apply ( lsst::afw::image::MaskedImage< PixelT > const &  image )

inline

Definition at line 87 of file ImageStatistics.h.

                                                                 {
            apply(image, -1);
        }

apply() [2/2]

template<typename PixelT>

void lsst::ip::diffim::ImageStatistics< PixelT >::apply ( lsst::afw::image::MaskedImage< PixelT > const &  image, int  core  )

inline

Definition at line 91 of file ImageStatistics.h.

                                                                           {
            reset();
            int y0, y1, x0, x1;
            if (core == -1) {
                y0 = 0;
                y1 = image.getHeight();
                x0 = 0;
                x1 = image.getWidth();
            }
            else {
                y0 = std::max(0, image.getHeight()/2 - core);
                y1 = std::min(image.getHeight(), image.getHeight()/2 + core + 1);
                x0 = std::max(0, image.getWidth()/2 - core);
                x1 = std::min(image.getWidth(), image.getWidth()/2 + core + 1);
            }
                
            for (int y = y0; y != y1; ++y) {
                for (x_iterator ptr = image.x_at(x0, y), end = image.x_at(x1, y); 
                     ptr != end; ++ptr) {
                    if (!((*ptr).mask() & _bpMask)) {
                        double const ivar = 1. / (*ptr).variance();
                        if (std::isfinite(ivar)) {
                            _xsum  += (*ptr).image() * sqrt(ivar);
                            _x2sum += (*ptr).image() * (*ptr).image() * ivar;
                            _npix  += 1;
                        }
                    }
                }
            }
            if ((!std::isfinite(_xsum)) || (!std::isfinite(_x2sum))) {
                throw LSST_EXCEPT(pexExcept::Exception, 
                                  "Nan/Inf in ImageStatistics.apply");
            }
        }

evaluateQuality()

template<typename PixelT>

bool lsst::ip::diffim::ImageStatistics< PixelT >::evaluateQuality ( lsst::pex::policy::Policy const &  policy )

inline

Definition at line 146 of file ImageStatistics.h.

                                                                {
            if ( fabs(getMean())     > policy.getDouble("maximumFootprintResidualMean") ) return false;
            if ( getRms()            > policy.getDouble("maximumFootprintResidualStd")  ) return false;
            return true;
        }           

getBpMask()

template<typename PixelT>

lsst::afw::image::MaskPixel lsst::ip::diffim::ImageStatistics< PixelT >::getBpMask ( )

inline

Definition at line 127 of file ImageStatistics.h.

{return _bpMask;}

getMean()

template<typename PixelT>

double lsst::ip::diffim::ImageStatistics< PixelT >::getMean ( ) const

inline

Definition at line 130 of file ImageStatistics.h.

                               { 
            return (_npix > 0) ? _xsum/_npix : std::numeric_limits<double>::quiet_NaN(); 
        }

getNpix()

template<typename PixelT>

int lsst::ip::diffim::ImageStatistics< PixelT >::getNpix ( ) const

inline

Definition at line 143 of file ImageStatistics.h.

{ return _npix; }

getRms()

template<typename PixelT>

double lsst::ip::diffim::ImageStatistics< PixelT >::getRms ( ) const

inline

Definition at line 139 of file ImageStatistics.h.

                              { 
            return sqrt(getVariance());
        }

getVariance()

template<typename PixelT>

double lsst::ip::diffim::ImageStatistics< PixelT >::getVariance ( ) const

inline

Definition at line 134 of file ImageStatistics.h.

                                   { 
            return (_npix > 1) ? (_x2sum/_npix - _xsum/_npix * _xsum/_npix) * _npix/(_npix-1.) : 
                std::numeric_limits<double>::quiet_NaN(); 
        }

reset()

template<typename PixelT>

void lsst::ip::diffim::ImageStatistics< PixelT >::reset ( )

inline

Definition at line 84 of file ImageStatistics.h.

{ _xsum = _x2sum = 0.; _npix = 0;}

setBpMask()

template<typename PixelT>

void lsst::ip::diffim::ImageStatistics< PixelT >::setBpMask ( lsst::afw::image::MaskPixel  bpMask )

inline

Definition at line 126 of file ImageStatistics.h.

{_bpMask = bpMask;}

---

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

• /j/snowflake/release/lsstsw/stack/Linux64/ip_diffim/18.1.0/include/lsst/ip/diffim/ImageStatistics.h