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def | __init__ (self, **kwargs) |
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def | run (self, template, science, sources, finalizedPsfApCorrCatalog=None) |
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def | runConvolveTemplate (self, template, science, selectSources) |
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def | runConvolveScience (self, template, science, selectSources) |
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def | finalize (self, template, science, difference, kernel, templateMatched=True, preConvMode=False, preConvKernel=None, spatiallyVarying=False) |
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Compute the image difference of a science and template image using
the Alard & Lupton (1998) algorithm.
Definition at line 191 of file subtractImages.py.
◆ __init__()
def lsst.ip.diffim.subtractImages.AlardLuptonSubtractTask.__init__ |
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self, |
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** |
kwargs |
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◆ _applyExternalCalibrations()
def lsst.ip.diffim.subtractImages.AlardLuptonSubtractTask._applyExternalCalibrations |
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self, |
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exposure, |
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finalizedPsfApCorrCatalog |
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Replace calibrations (psf, and ApCorrMap) on this exposure with external ones.".
Parameters
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exposure : `lsst.afw.image.exposure.Exposure`
Input exposure to adjust calibrations.
finalizedPsfApCorrCatalog : `lsst.afw.table.ExposureCatalog`
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
-------
exposure : `lsst.afw.image.exposure.Exposure`
Exposure with adjusted calibrations.
Definition at line 211 of file subtractImages.py.
◆ _checkMask()
def lsst.ip.diffim.subtractImages.AlardLuptonSubtractTask._checkMask |
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mask, |
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sources, |
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badMaskPlanes |
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staticprotected |
Exclude sources that are located on masked pixels.
Parameters
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mask : `lsst.afw.image.Mask`
The image mask plane to use to reject sources
based on the location of their centroid on the ccd.
sources : `lsst.afw.table.SourceCatalog`
The source catalog to evaluate.
badMaskPlanes : `list` of `str`
List of the names of the mask planes to exclude.
Returns
-------
flags : `numpy.ndarray` of `bool`
Array indicating whether each source in the catalog should be
kept (True) or rejected (False) based on the value of the
mask plane at its location.
Definition at line 633 of file subtractImages.py.
◆ _convolveExposure()
def lsst.ip.diffim.subtractImages.AlardLuptonSubtractTask._convolveExposure |
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exposure, |
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kernel, |
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convolutionControl, |
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bbox = None , |
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psf = None , |
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photoCalib = None |
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Convolve an exposure with the given kernel.
Parameters
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exposure : `lsst.afw.Exposure`
exposure to convolve.
kernel : `lsst.afw.math.LinearCombinationKernel`
PSF matching kernel computed in the ``makeKernel`` subtask.
convolutionControl : `lsst.afw.math.ConvolutionControl`
Configuration for convolve algorithm.
bbox : `lsst.geom.Box2I`, optional
Bounding box to trim the convolved exposure to.
psf : `lsst.afw.detection.Psf`, optional
Point spread function (PSF) to set for the convolved exposure.
photoCalib : `lsst.afw.image.PhotoCalib`, optional
Photometric calibration of the convolved exposure.
Returns
-------
convolvedExp : `lsst.afw.Exposure`
The convolved image.
Definition at line 550 of file subtractImages.py.
◆ _prepareInputs()
def lsst.ip.diffim.subtractImages.AlardLuptonSubtractTask._prepareInputs |
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self, |
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template, |
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science, |
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finalizedPsfApCorrCatalog = None |
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Perform preparatory calculations common to all Alard&Lupton Tasks.
Parameters
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template : `lsst.afw.image.ExposureF`
Template exposure, warped to match the science exposure.
The variance plane of the template image is modified in place.
science : `lsst.afw.image.ExposureF`
Science exposure to subtract from the template.
The variance plane of the science image is modified in place.
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.
Definition at line 661 of file subtractImages.py.
◆ _sourceSelector()
def lsst.ip.diffim.subtractImages.AlardLuptonSubtractTask._sourceSelector |
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self, |
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sources, |
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mask |
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Select sources from a catalog that meet the selection criteria.
Parameters
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sources : `lsst.afw.table.SourceCatalog`
Input source catalog to select sources from.
mask : `lsst.afw.image.Mask`
The image mask plane to use to reject sources
based on their location on the ccd.
Returns
-------
selectSources : `lsst.afw.table.SourceCatalog`
The input source catalog, with flagged and low signal-to-noise
sources removed.
Raises
------
RuntimeError
If there are too few sources to compute the PSF matching kernel
remaining after source selection.
Definition at line 589 of file subtractImages.py.
◆ _validateExposures()
def lsst.ip.diffim.subtractImages.AlardLuptonSubtractTask._validateExposures |
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template, |
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science |
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staticprotected |
Check that the WCS of the two Exposures match, and the template bbox
contains the science bbox.
Parameters
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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.
Raises
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AssertionError
Raised if the WCS of the template is not equal to the science WCS,
or if the science image is not fully contained in the template
bounding box.
Definition at line 523 of file subtractImages.py.
◆ finalize()
def lsst.ip.diffim.subtractImages.AlardLuptonSubtractTask.finalize |
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self, |
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template, |
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science, |
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difference, |
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kernel, |
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templateMatched = True , |
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preConvMode = False , |
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preConvKernel = None , |
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spatiallyVarying = False |
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Decorrelate the difference image to undo the noise correlations
caused by convolution.
Parameters
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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 471 of file subtractImages.py.
◆ run()
def lsst.ip.diffim.subtractImages.AlardLuptonSubtractTask.run |
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self, |
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template, |
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science, |
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sources, |
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finalizedPsfApCorrCatalog = None |
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PSF match, subtract, and decorrelate two images.
Parameters
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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.Function2D`
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
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RuntimeError
If an unsupported convolution mode is supplied.
RuntimeError
If there are too few sources to calculate the PSF matching kernel.
lsst.pipe.base.NoWorkFound
Raised if fraction of good pixels, defined as not having NO_DATA
set, is less then the configured requiredTemplateFraction
Reimplemented in lsst.ip.diffim.subtractImages.AlardLuptonPreconvolveSubtractTask.
Definition at line 252 of file subtractImages.py.
◆ runConvolveScience()
def lsst.ip.diffim.subtractImages.AlardLuptonSubtractTask.runConvolveScience |
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self, |
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template, |
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science, |
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selectSources |
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Convolve the science image with a PSF-matching kernel and subtract the template image.
Parameters
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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.
selectSources : `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.Function2D`
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 406 of file subtractImages.py.
◆ runConvolveTemplate()
def lsst.ip.diffim.subtractImages.AlardLuptonSubtractTask.runConvolveTemplate |
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self, |
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template, |
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science, |
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selectSources |
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Convolve the template image with a PSF-matching kernel and subtract
from the science image.
Parameters
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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.
selectSources : `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.Function2D`
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 353 of file subtractImages.py.
◆ _DefaultName
str lsst.ip.diffim.subtractImages.AlardLuptonSubtractTask._DefaultName = "alardLuptonSubtract" |
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staticprotected |
◆ ConfigClass
◆ convolutionControl
lsst.ip.diffim.subtractImages.AlardLuptonSubtractTask.convolutionControl |
The documentation for this class was generated from the following file: