Class to calculate difference image statistics. More...

#include <ImageStatistics.h>

Public Types
typedef boost::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)

Private Attributes
double	_xsum

double	_x2sum

int	_npix

lsst::afw::image::MaskPixel	_bpMask

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 58 of file ImageStatistics.h.

Member Typedef Documentation

template<typename PixelT>

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

Definition at line 60 of file ImageStatistics.h.

template<typename PixelT>

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

Definition at line 61 of file ImageStatistics.h.

Constructor & Destructor Documentation

template<typename PixelT>

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

inline

Definition at line 63 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) {
                     lsst::pex::logging::TTrace<6>("lsst.ip.diffim.ImageStatistics",
                                                   "Cannot update bad bit mask with %s", (*mi).c_str());
                     lsst::pex::logging::TTrace<7>("lsst.ip.diffim.ImageStatistics",
                                                   e.what());
                 }
             }
         } ;

template<typename PixelT>

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

inlinevirtual

Definition at line 80 of file ImageStatistics.h.

80 {} ;

Member Function Documentation

template<typename PixelT>

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

inline

Definition at line 86 of file ImageStatistics.h.

                                                                  {
             apply(image, -1);
         }

template<typename PixelT>

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

inline

Definition at line 90 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 (lsst::utils::lsst_isfinite(ivar)) {
                             _xsum  += (*ptr).image() * sqrt(ivar);
                             _x2sum += (*ptr).image() * (*ptr).image() * ivar;
                             _npix  += 1;
                         }
                     }
                 }
             }
             if ((!lsst::utils::lsst_isfinite(_xsum)) || (!lsst::utils::lsst_isfinite(_x2sum))) {
                 throw LSST_EXCEPT(pexExcept::Exception, 
                                   "Nan/Inf in ImageStatistics.apply");
             }
         }

template<typename PixelT>

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

inline

Definition at line 145 of file ImageStatistics.h.

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

template<typename PixelT>

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

inline

Definition at line 126 of file ImageStatistics.h.

126 {return _bpMask;}

lsst::ip::diffim::ImageStatistics::_bpMask

lsst::afw::image::MaskPixel _bpMask

Definition: ImageStatistics.h:155

template<typename PixelT>

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

inline

Definition at line 129 of file ImageStatistics.h.

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

template<typename PixelT>

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

inline

Definition at line 142 of file ImageStatistics.h.

142 { return _npix; }

lsst::ip::diffim::ImageStatistics::_npix

int _npix

Definition: ImageStatistics.h:154

template<typename PixelT>

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

inline

Definition at line 138 of file ImageStatistics.h.

                               { 
             return sqrt(getVariance());
         }

template<typename PixelT>

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

inline

Definition at line 133 of file ImageStatistics.h.

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