LSSTApplications: lsst.meas.algorithms.detection Namespace Reference

LSSTApplications 8.0.0.0+107,8.0.0.1+13,9.1+18,9.2,master-g084aeec0a4,master-g0aced2eed8+6,master-g15627eb03c,master-g28afc54ef9,master-g3391ba5ea0,master-g3d0fb8ae5f,master-g4432ae2e89+36,master-g5c3c32f3ec+17,master-g60f1e072bb+1,master-g6a3ac32d1b,master-g76a88a4307+1,master-g7bce1f4e06+57,master-g8ff4092549+31,master-g98e65bf68e,master-ga6b77976b1+53,master-gae20e2b580+3,master-gb584cd3397+53,master-gc5448b162b+1,master-gc54cf9771d,master-gc69578ece6+1,master-gcbf758c456+22,master-gcec1da163f+63,master-gcf15f11bcc,master-gd167108223,master-gf44c96c709

LSSTDataManagementBasePackage

Classes
class	BackgroundConfig
	Config for background estimation. More...

class	SourceDetectionConfig
	Configuration parameters for the SourceDetectionTask. More...

class	SourceDetectionTask
	Detect positive and negative sources on an exposure and return a new table.SourceCatalog. More...

Functions
def	addExposures
	Add a set of exposures together. More...

def	getBackground
	Estimate the background of an image (a thin layer on lsst.afw.math.makeBackground) More...

def	estimateBackground
	Estimate exposure's background using parameters in backgroundConfig. More...

Variables
tuple	__all__

Function Documentation

def lsst.meas.algorithms.detection.addExposures ( exposureList )

Add a set of exposures together.

Parameters

[in] exposureList sequence of exposures to add

Returns: an exposure of the same size as each exposure in exposureList, with the metadata from exposureList[0] and a masked image equal to the sum of all the exposure's masked images.

Exceptions

LsstException if the exposures do not all have the same dimensions (but does not check xy0)

Definition at line 507 of file detection.py.

 
 def addExposures(exposureList):
     """!Add a set of exposures together.
 
     \param[in] exposureList  sequence of exposures to add
 
     \return an exposure of the same size as each exposure in exposureList,
     with the metadata from exposureList[0] and a masked image equal to the
     sum of all the exposure's masked images.
 
     \throw LsstException if the exposures do not all have the same dimensions (but does not check xy0)
     """
     exposure0 = exposureList[0]
     image0 = exposure0.getMaskedImage()
 
     addedImage = image0.Factory(image0, True)
     addedImage.setXY0(image0.getXY0())
 
     for exposure in exposureList[1:]:
         image = exposure.getMaskedImage()
         addedImage += image
 
     addedExposure = exposure0.Factory(addedImage, exposure0.getWcs())
     return addedExposure

lsst::meas::algorithms.detection.addExposures

def addExposures

Add a set of exposures together.

Definition: detection.py:507

def lsst.meas.algorithms.detection.estimateBackground	(	exposure,
		backgroundConfig,
		subtract = `True`,
		stats = `True`,
		statsKeys = `None`
	)

Estimate exposure's background using parameters in backgroundConfig.

If subtract is true, make a copy of the exposure and subtract the background. If `stats` is True, measure the mean and variance of the background and add them to the background-subtracted exposure's metadata with keys "BGMEAN" and "BGVAR", or the keys given in `statsKeys` (2-tuple of strings).

Return background, backgroundSubtractedExposure

Definition at line 567 of file detection.py.

 
                        statsKeys=None):
     """!Estimate exposure's background using parameters in backgroundConfig.
 
     If subtract is true, make a copy of the exposure and subtract the background.  
     If `stats` is True, measure the mean and variance of the background and
     add them to the background-subtracted exposure's metadata with keys
     "BGMEAN" and "BGVAR", or the keys given in `statsKeys` (2-tuple of strings).
     
     Return background, backgroundSubtractedExposure
     """
     displayBackground = lsstDebug.Info(__name__).displayBackground
 
     maskedImage = exposure.getMaskedImage()
 
     background = getBackground(maskedImage, backgroundConfig)
 
     if not background:
         raise RuntimeError, "Unable to estimate background for exposure"
 
     bgimg = None
     
     if displayBackground > 1:
         bgimg = background.getImageF()
         ds9.mtv(bgimg, title="background", frame=1)
 
     if not subtract:
         return background, None
 
     bbox = maskedImage.getBBox()
     backgroundSubtractedExposure = exposure.Factory(exposure, bbox, afwImage.PARENT, True)
     copyImage = backgroundSubtractedExposure.getMaskedImage().getImage()
     if bgimg is None:
         bgimg = background.getImageF()
     copyImage -= bgimg
 
     # Record statistics of the background in the bgsub exposure metadata.
     # (lsst.daf.base.PropertySet)
     if stats:
         if statsKeys is None:
             mnkey  = 'BGMEAN'
             varkey = 'BGVAR'
         else:
             mnkey,varkey = statsKeys
         meta = backgroundSubtractedExposure.getMetadata()
         s = afwMath.makeStatistics(bgimg, afwMath.MEAN | afwMath.VARIANCE)
         bgmean = s.getValue(afwMath.MEAN)
         bgvar  = s.getValue(afwMath.VARIANCE)
         meta.addDouble(mnkey,  bgmean)
         meta.addDouble(varkey,  bgvar)
     
     if displayBackground:
         ds9.mtv(backgroundSubtractedExposure, title="subtracted")
 
     return background, backgroundSubtractedExposure
 estimateBackground.ConfigClass = BackgroundConfig

def lsst.meas.algorithms.detection.getBackground	(	image,
		backgroundConfig,
		nx = `0`,
		ny = `0`,
		algorithm = `None`
	)

Estimate the background of an image (a thin layer on lsst.afw.math.makeBackground)

Parameters

[in]	image	image whose background is to be computed
[in]	backgroundConfig	configuration (a BackgroundConfig)
[in]	nx	number of x bands; 0 for default
[in]	ny	number of y bands; 0 for default
[in]	algorithm	name of interpolation algorithm; see lsst.afw.math.BackgroundControl for details

Definition at line 531 of file detection.py.

 
 def getBackground(image, backgroundConfig, nx=0, ny=0, algorithm=None):
     """!Estimate the background of an image (a thin layer on lsst.afw.math.makeBackground)
 
     \param[in] image  image whose background is to be computed
     \param[in] backgroundConfig  configuration (a BackgroundConfig)
     \param[in] nx  number of x bands; 0 for default
     \param[in] ny  number of y bands; 0 for default
     \param[in] algorithm  name of interpolation algorithm; see lsst.afw.math.BackgroundControl for details
     """
     backgroundConfig.validate();
 
     if not nx:
         nx = image.getWidth()//backgroundConfig.binSize + 1
     if not ny:
         ny = image.getHeight()//backgroundConfig.binSize + 1
 
     sctrl = afwMath.StatisticsControl()
     sctrl.setAndMask(reduce(lambda x, y: x | image.getMask().getPlaneBitMask(y),
                             backgroundConfig.ignoredPixelMask, 0x0))
     sctrl.setNanSafe(backgroundConfig.isNanSafe)
 
     pl = pexLogging.Debug("meas.utils.sourceDetection.getBackground")
     pl.debug(3, "Ignoring mask planes: %s" % ", ".join(backgroundConfig.ignoredPixelMask))
 
     if not algorithm:
         algorithm = backgroundConfig.algorithm
         
     bctrl = afwMath.BackgroundControl(algorithm, nx, ny,
                                       backgroundConfig.undersampleStyle, sctrl,
                                       backgroundConfig.statisticsProperty)
 
     return afwMath.makeBackground(image, bctrl)
 
 getBackground.ConfigClass = BackgroundConfig

lsst::afw::math::makeBackground

boost::shared_ptr< Background > makeBackground(ImageT const &img, BackgroundControl const &bgCtrl)

A convenience function that uses function overloading to make the correct type of Background...

Definition: Background.h:446

lsst::afw::math::BackgroundControl

Pass parameters to a Background object.

Definition: Background.h:62

lsst::afw::math::StatisticsControl

Pass parameters to a Statistics objectA class to pass parameters which control how the stats are calc...

Definition: Statistics.h:92

lsst::meas::algorithms.detection.getBackground

def getBackground

Estimate the background of an image (a thin layer on lsst.afw.math.makeBackground) ...

Definition: detection.py:531

lsst::pex::logging::Debug

Definition: Debug.h:75

Classes

Functions

Variables

Function Documentation

Variable Documentation