lsst.ip.diffim ga4827df335+6f80ac3879
Public Member Functions | Public Attributes | Static Public Attributes | List of all members
lsst.ip.diffim.subtractImages.AlardLuptonSubtractTask Class Reference
Inheritance diagram for lsst.ip.diffim.subtractImages.AlardLuptonSubtractTask:

Public Member Functions

def __init__ (self, **kwargs)
 
def run (self, template, science, sources, finalizedPsfApCorrCatalog=None)
 
def runConvolveTemplate (self, template, science, sources)
 
def runConvolveScience (self, template, science, sources)
 
def finalize (self, template, science, difference, kernel, templateMatched=True, preConvMode=False, preConvKernel=None, spatiallyVarying=False)
 

Public Attributes

 convolutionControl
 

Static Public Attributes

 ConfigClass = AlardLuptonSubtractConfig
 

Detailed Description

Compute the image difference of a science and template image using
the Alard & Lupton (1998) algorithm.

Definition at line 169 of file subtractImages.py.

Constructor & Destructor Documentation

◆ __init__()

def lsst.ip.diffim.subtractImages.AlardLuptonSubtractTask.__init__ (   self,
**  kwargs 
)

Definition at line 176 of file subtractImages.py.

Member Function Documentation

◆ finalize()

def lsst.ip.diffim.subtractImages.AlardLuptonSubtractTask.finalize (   self,
  template,
  science,
  difference,
  kernel,
  templateMatched = True,
  preConvMode = False,
  preConvKernel = None,
  spatiallyVarying = False 
)
Decorrelate the difference image to undo the noise correlations
caused by convolution.

Parameters
----------
template : `lsst.afw.image.ExposureF`
    Template exposure, warped to match the science exposure.
science : `lsst.afw.image.ExposureF`
    Science exposure to subtract from the template.
difference : `lsst.afw.image.ExposureF`
    Result of subtracting template and science.
kernel : `lsst.afw.math.Kernel`
    An (optionally spatially-varying) PSF matching kernel
templateMatched : `bool`, optional
    Was the template PSF-matched to the science image?
preConvMode : `bool`, optional
    Was the science image preconvolved with its own PSF
    before PSF matching the template?
preConvKernel : `lsst.afw.detection.Psf`, optional
    If not `None`, then the science image was pre-convolved with
    (the reflection of) this kernel. Must be normalized to sum to 1.
spatiallyVarying : `bool`, optional
    Compute the decorrelation kernel spatially varying across the image?

Returns
-------
correctedExposure : `lsst.afw.image.ExposureF`
    The decorrelated image difference.

Definition at line 440 of file subtractImages.py.

◆ run()

def lsst.ip.diffim.subtractImages.AlardLuptonSubtractTask.run (   self,
  template,
  science,
  sources,
  finalizedPsfApCorrCatalog = None 
)
PSF match, subtract, and decorrelate two images.

Parameters
----------
template : `lsst.afw.image.ExposureF`
    Template exposure, warped to match the science exposure.
science : `lsst.afw.image.ExposureF`
    Science exposure to subtract from the template.
sources : `lsst.afw.table.SourceCatalog`
    Identified sources on the science exposure. This catalog is used to
    select sources in order to perform the AL PSF matching on stamp
    images around them.
finalizedPsfApCorrCatalog : `lsst.afw.table.ExposureCatalog`, optional
    Exposure catalog with finalized psf models and aperture correction
    maps to be applied if config.doApplyFinalizedPsf=True.  Catalog uses
    the detector id for the catalog id, sorted on id for fast lookup.

Returns
-------
results : `lsst.pipe.base.Struct`
    ``difference`` : `lsst.afw.image.ExposureF`
        Result of subtracting template and science.
    ``matchedTemplate`` : `lsst.afw.image.ExposureF`
        Warped and PSF-matched template exposure.
    ``backgroundModel`` : `lsst.afw.math.Chebyshev1Function2D`
        Background model that was fit while solving for the PSF-matching kernel
    ``psfMatchingKernel`` : `lsst.afw.math.Kernel`
        Kernel used to PSF-match the convolved image.

Raises
------
RuntimeError
    If an unsupported convolution mode is supplied.
lsst.pipe.base.NoWorkFound
    Raised if fraction of good pixels, defined as not having NO_DATA
    set, is less then the configured requiredTemplateFraction

Definition at line 230 of file subtractImages.py.

◆ runConvolveScience()

def lsst.ip.diffim.subtractImages.AlardLuptonSubtractTask.runConvolveScience (   self,
  template,
  science,
  sources 
)
Convolve the science image with a PSF-matching kernel and subtract the template image.

Parameters
----------
template : `lsst.afw.image.ExposureF`
    Template exposure, warped to match the science exposure.
science : `lsst.afw.image.ExposureF`
    Science exposure to subtract from the template.
sources : `lsst.afw.table.SourceCatalog`
    Identified sources on the science exposure. This catalog is used to
    select sources in order to perform the AL PSF matching on stamp
    images around them.

Returns
-------
results : `lsst.pipe.base.Struct`

    ``difference`` : `lsst.afw.image.ExposureF`
        Result of subtracting template and science.
    ``matchedTemplate`` : `lsst.afw.image.ExposureF`
        Warped template exposure. Note that in this case, the template
        is not PSF-matched to the science image.
    ``backgroundModel`` : `lsst.afw.math.Chebyshev1Function2D`
        Background model that was fit while solving for the PSF-matching kernel
    ``psfMatchingKernel`` : `lsst.afw.math.Kernel`
       Kernel used to PSF-match the science image to the template.

Definition at line 377 of file subtractImages.py.

◆ runConvolveTemplate()

def lsst.ip.diffim.subtractImages.AlardLuptonSubtractTask.runConvolveTemplate (   self,
  template,
  science,
  sources 
)
Convolve the template image with a PSF-matching kernel and subtract
from the science image.

Parameters
----------
template : `lsst.afw.image.ExposureF`
    Template exposure, warped to match the science exposure.
science : `lsst.afw.image.ExposureF`
    Science exposure to subtract from the template.
sources : `lsst.afw.table.SourceCatalog`
    Identified sources on the science exposure. This catalog is used to
    select sources in order to perform the AL PSF matching on stamp
    images around them.

Returns
-------
results : `lsst.pipe.base.Struct`

    ``difference`` : `lsst.afw.image.ExposureF`
        Result of subtracting template and science.
    ``matchedTemplate`` : `lsst.afw.image.ExposureF`
        Warped and PSF-matched template exposure.
    ``backgroundModel`` : `lsst.afw.math.Chebyshev1Function2D`
        Background model that was fit while solving for the PSF-matching kernel
    ``psfMatchingKernel`` : `lsst.afw.math.Kernel`
        Kernel used to PSF-match the template to the science image.

Definition at line 326 of file subtractImages.py.

Member Data Documentation

◆ ConfigClass

lsst.ip.diffim.subtractImages.AlardLuptonSubtractTask.ConfigClass = AlardLuptonSubtractConfig
static

Definition at line 173 of file subtractImages.py.

◆ convolutionControl

lsst.ip.diffim.subtractImages.AlardLuptonSubtractTask.convolutionControl

Definition at line 183 of file subtractImages.py.


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