ZogyImagePsfMatchTask¶
- class lsst.ip.diffim.ZogyImagePsfMatchTask(*args, **kwargs)¶
Bases:
ImagePsfMatchTask
Task to perform Zogy PSF matching and image subtraction.
This class inherits from ImagePsfMatchTask to contain the _warper subtask and related methods.
Methods Summary
Empty (clear) the metadata for this Task and all sub-Tasks.
Get schema catalogs for all tasks in the hierarchy, combining the results into a single dict.
Get metadata for all tasks.
Get the task name as a hierarchical name including parent task names.
getFwhmPix
(psf[, position])Return the FWHM in pixels of a Psf.
getName
()Get the name of the task.
Get the schemas generated by this task.
getSelectSources
(exposure[, sigma, ...])Get sources to use for Psf-matching.
Get a dictionary of all tasks as a shallow copy.
makeCandidateList
(templateExposure, ...[, ...])Make a list of acceptable KernelCandidates.
makeField
(doc)Make a
lsst.pex.config.ConfigurableField
for this task.makeKernelBasisList
([targetFwhmPix, ...])Wrapper to set log messages for
lsst.ip.diffim.makeKernelBasisList
.makeSubtask
(name, **keyArgs)Create a subtask as a new instance as the
name
attribute of this task.matchExposures
(templateExposure, scienceExposure)Warp and PSF-match an exposure to the reference.
matchMaskedImages
(templateMaskedImage, ...)PSF-match a MaskedImage (templateMaskedImage) to a reference MaskedImage (scienceMaskedImage).
run
(scienceExposure, templateExposure[, ...])Register, PSF-match, and subtract two Exposures,
scienceExposure - templateExposure
using the ZOGY algorithm.subtractExposures
(templateExposure, ...)Register, Psf-match and subtract two Exposures.
subtractMaskedImages
(templateExposure, ...)Psf-match and subtract two MaskedImages.
timer
(name[, logLevel])Context manager to log performance data for an arbitrary block of code.
Methods Documentation
- getAllSchemaCatalogs() Dict[str, Any] ¶
Get schema catalogs for all tasks in the hierarchy, combining the results into a single dict.
- Returns:
- schemacatalogs
dict
Keys are butler dataset type, values are a empty catalog (an instance of the appropriate
lsst.afw.table
Catalog type) for all tasks in the hierarchy, from the top-level task down through all subtasks.
- schemacatalogs
Notes
This method may be called on any task in the hierarchy; it will return the same answer, regardless.
The default implementation should always suffice. If your subtask uses schemas the override
Task.getSchemaCatalogs
, not this method.
- getFullMetadata() TaskMetadata ¶
Get metadata for all tasks.
- Returns:
- metadata
TaskMetadata
The keys are the full task name. Values are metadata for the top-level task and all subtasks, sub-subtasks, etc.
- metadata
Notes
The returned metadata includes timing information (if
@timer.timeMethod
is used) and any metadata set by the task. The name of each item consists of the full task name with.
replaced by:
, followed by.
and the name of the item, e.g.:topLevelTaskName:subtaskName:subsubtaskName.itemName
using
:
in the full task name disambiguates the rare situation that a task has a subtask and a metadata item with the same name.
- getFullName() str ¶
Get the task name as a hierarchical name including parent task names.
- Returns:
- fullName
str
The full name consists of the name of the parent task and each subtask separated by periods. For example:
The full name of top-level task “top” is simply “top”.
The full name of subtask “sub” of top-level task “top” is “top.sub”.
The full name of subtask “sub2” of subtask “sub” of top-level task “top” is “top.sub.sub2”.
- fullName
- getFwhmPix(psf, position=None)¶
Return the FWHM in pixels of a Psf.
- getSchemaCatalogs() Dict[str, Any] ¶
Get the schemas generated by this task.
- Returns:
- schemaCatalogs
dict
Keys are butler dataset type, values are an empty catalog (an instance of the appropriate
lsst.afw.table
Catalog type) for this task.
- schemaCatalogs
See also
Task.getAllSchemaCatalogs
Notes
Warning
Subclasses that use schemas must override this method. The default implementation returns an empty dict.
This method may be called at any time after the Task is constructed, which means that all task schemas should be computed at construction time, not when data is actually processed. This reflects the philosophy that the schema should not depend on the data.
Returning catalogs rather than just schemas allows us to save e.g. slots for SourceCatalog as well.
- getSelectSources(exposure, sigma=None, doSmooth=True, idFactory=None)¶
Get sources to use for Psf-matching.
This method runs detection and measurement on an exposure. The returned set of sources will be used as candidates for Psf-matching.
- Parameters:
- Returns:
- selectSources
source catalog containing candidates for the Psf-matching
- getTaskDict() Dict[str, ReferenceType[Task]] ¶
Get a dictionary of all tasks as a shallow copy.
- Returns:
- taskDict
dict
Dictionary containing full task name: task object for the top-level task and all subtasks, sub-subtasks, etc.
- taskDict
- makeCandidateList(templateExposure, scienceExposure, kernelSize, candidateList=None)¶
Make a list of acceptable KernelCandidates.
Accept or generate a list of candidate sources for Psf-matching, and examine the Mask planes in both of the images for indications of bad pixels
- Parameters:
- templateExposure
lsst.afw.image.Exposure
Exposure that will be convolved
- scienceExposure
lsst.afw.image.Exposure
Exposure that will be matched-to
- kernelSize
float
Dimensions of the Psf-matching Kernel, used to grow detection footprints
- candidateList
list
, optional List of Sources to examine. Elements must be of type afw.table.Source or a type that wraps a Source and has a getSource() method, such as meas.algorithms.PsfCandidateF.
- templateExposure
- Returns:
- classmethod makeField(doc: str) ConfigurableField ¶
Make a
lsst.pex.config.ConfigurableField
for this task.- Parameters:
- doc
str
Help text for the field.
- doc
- Returns:
- configurableField
lsst.pex.config.ConfigurableField
A
ConfigurableField
for this task.
- configurableField
Examples
Provides a convenient way to specify this task is a subtask of another task.
Here is an example of use:
class OtherTaskConfig(lsst.pex.config.Config): aSubtask = ATaskClass.makeField("brief description of task")
- makeKernelBasisList(targetFwhmPix=None, referenceFwhmPix=None, basisDegGauss=None, basisSigmaGauss=None, metadata=None)¶
Wrapper to set log messages for
lsst.ip.diffim.makeKernelBasisList
.- Parameters:
- targetFwhmPix
float
, optional Passed on to
lsst.ip.diffim.generateAlardLuptonBasisList
. Not used for delta function basis sets.- referenceFwhmPix
float
, optional Passed on to
lsst.ip.diffim.generateAlardLuptonBasisList
. Not used for delta function basis sets.- basisDegGauss
list
ofint
, optional Passed on to
lsst.ip.diffim.generateAlardLuptonBasisList
. Not used for delta function basis sets.- basisSigmaGauss
list
ofint
, optional Passed on to
lsst.ip.diffim.generateAlardLuptonBasisList
. Not used for delta function basis sets.- metadata
lsst.daf.base.PropertySet
, optional Passed on to
lsst.ip.diffim.generateAlardLuptonBasisList
. Not used for delta function basis sets.
- targetFwhmPix
- Returns:
- basisList:
list
oflsst.afw.math.kernel.FixedKernel
List of basis kernels.
- basisList:
- makeSubtask(name: str, **keyArgs: Any) None ¶
Create a subtask as a new instance as the
name
attribute of this task.- Parameters:
- name
str
Brief name of the subtask.
- keyArgs
Extra keyword arguments used to construct the task. The following arguments are automatically provided and cannot be overridden:
“config”.
“parentTask”.
- name
Notes
The subtask must be defined by
Task.config.name
, an instance ofConfigurableField
orRegistryField
.
- matchExposures(templateExposure, scienceExposure, templateFwhmPix=None, scienceFwhmPix=None, candidateList=None, doWarping=True, convolveTemplate=True)¶
Warp and PSF-match an exposure to the reference.
Do the following, in order:
- Warp templateExposure to match scienceExposure,
if doWarping True and their WCSs do not already match
- Determine a PSF matching kernel and differential background model
that matches templateExposure to scienceExposure
Convolve templateExposure by PSF matching kernel
- Parameters:
- templateExposure
lsst.afw.image.Exposure
Exposure to warp and PSF-match to the reference masked image
- scienceExposure
lsst.afw.image.Exposure
Exposure whose WCS and PSF are to be matched to
- templateFwhmPix :`float`
FWHM (in pixels) of the Psf in the template image (image to convolve)
- scienceFwhmPix
float
FWHM (in pixels) of the Psf in the science image
- candidateList
list
, optional a list of footprints/maskedImages for kernel candidates; if
None
then source detection is run.Currently supported: list of Footprints or measAlg.PsfCandidateF
- doWarping
bool
what to do if
templateExposure
andscienceExposure
WCSs do not match:- convolveTemplate
bool
Whether to convolve the template image or the science image:
- templateExposure
- Returns:
- results
lsst.pipe.base.Struct
An
lsst.pipe.base.Struct
containing these fields:matchedImage
the PSF-matched exposure =Warped
templateExposure
convolved by psfMatchingKernel. This has:the same parent bbox, Wcs and PhotoCalib as scienceExposure
the same filter as templateExposure
no Psf (because the PSF-matching process does not compute one)
psfMatchingKernel
: the PSF matching kernelbackgroundModel
: differential background modelkernelCellSet
: SpatialCellSet used to solve for the PSF matching kernel
- results
- Raises:
- RuntimeError
Raised if doWarping is False and
templateExposure
andscienceExposure
WCSs do not match
- matchMaskedImages(templateMaskedImage, scienceMaskedImage, candidateList, templateFwhmPix=None, scienceFwhmPix=None)¶
PSF-match a MaskedImage (templateMaskedImage) to a reference MaskedImage (scienceMaskedImage).
Do the following, in order:
- Determine a PSF matching kernel and differential background model
that matches templateMaskedImage to scienceMaskedImage
Convolve templateMaskedImage by the PSF matching kernel
- Parameters:
- templateMaskedImage
lsst.afw.image.MaskedImage
masked image to PSF-match to the reference masked image; must be warped to match the reference masked image
- scienceMaskedImage
lsst.afw.image.MaskedImage
maskedImage whose PSF is to be matched to
- templateFwhmPix
float
FWHM (in pixels) of the Psf in the template image (image to convolve)
- scienceFwhmPix
float
FWHM (in pixels) of the Psf in the science image
- candidateList
list
, optional A list of footprints/maskedImages for kernel candidates; if
None
then source detection is run.Currently supported: list of Footprints or measAlg.PsfCandidateF
- templateMaskedImage
- Returns:
- result
callable
- An
lsst.pipe.base.Struct
containing these fields:
- psfMatchedMaskedImage: the PSF-matched masked image =
templateMaskedImage
convolved with psfMatchingKernel. This has the same xy0, dimensions and wcs asscienceMaskedImage
.
- psfMatchingKernel: the PSF matching kernel
- backgroundModel: differential background model
- kernelCellSet: SpatialCellSet used to solve for the PSF matching kernel
- result
- Raises:
- RuntimeError
Raised if input images have different dimensions
- run(scienceExposure, templateExposure, doWarping=True)¶
Register, PSF-match, and subtract two Exposures,
scienceExposure - templateExposure
using the ZOGY algorithm.- Parameters:
- templateExposure
lsst.afw.image.Exposure
exposure to be warped to scienceExposure.
- scienceExposure
lsst.afw.image.Exposure
reference Exposure.
- doWarping
bool
what to do if templateExposure’s and scienceExposure’s WCSs do not match: - if True then warp templateExposure to match scienceExposure - if False then raise an Exception
- templateExposure
- Returns:
- results
lsst.pipe.base.Struct
containing these fields: - subtractedExposure:
lsst.afw.image.Exposure
The subtraction result.
- subtractedExposure:
- warpedExposure:
lsst.afw.image.Exposure
orNone
templateExposure after warping to match scienceExposure
- warpedExposure:
- results
Notes
- Do the following, in order:
Warp templateExposure to match scienceExposure, if their WCSs do not already match
Compute subtracted exposure ZOGY image subtraction algorithm on the two exposures
This is the new entry point of the task as of DM-25115.
- subtractExposures(templateExposure, scienceExposure, *args)¶
Register, Psf-match and subtract two Exposures.
Do the following, in order:
Warp templateExposure to match scienceExposure, if their WCSs do not already match
- Determine a PSF matching kernel and differential background model
that matches templateExposure to scienceExposure
PSF-match templateExposure to scienceExposure
Compute subtracted exposure (see return values for equation).
- Parameters:
- templateExposure
lsst.afw.image.ExposureF
Exposure to PSF-match to scienceExposure
- scienceExposure
lsst.afw.image.ExposureF
Reference Exposure
- templateFwhmPix
float
FWHM (in pixels) of the Psf in the template image (image to convolve)
- scienceFwhmPix
float
FWHM (in pixels) of the Psf in the science image
- candidateList
list
, optional A list of footprints/maskedImages for kernel candidates; if
None
then source detection is run.Currently supported: list of Footprints or measAlg.PsfCandidateF
- doWarping
bool
What to do if
templateExposure`
andscienceExposure
WCSs do not match:- convolveTemplate
bool
Convolve the template image or the science image
- templateExposure
- Returns:
- result
lsst.pipe.base.Struct
An
lsst.pipe.base.Struct
containing these fields:subtractedExposure
subtracted ExposurescienceExposure - (matchedImage + backgroundModel)
matchedImage
templateExposure
after warping to matchtemplateExposure
(if doWarping true), and convolving with psfMatchingKernel
psfMatchingKernel
: PSF matching kernelbackgroundModel
: differential background modelkernelCellSet
: SpatialCellSet used to determine PSF matching kernel
- result
- subtractMaskedImages(templateExposure, scienceExposure, *args)¶
Psf-match and subtract two MaskedImages.
Do the following, in order:
PSF-match templateMaskedImage to scienceMaskedImage
Determine the differential background
- Return the difference: scienceMaskedImage
((warped templateMaskedImage convolved with psfMatchingKernel) + backgroundModel)
- Parameters:
- templateMaskedImage
lsst.afw.image.MaskedImage
MaskedImage to PSF-match to
scienceMaskedImage
- scienceMaskedImage
lsst.afw.image.MaskedImage
Reference MaskedImage
- templateFwhmPix
float
FWHM (in pixels) of the Psf in the template image (image to convolve)
- scienceFwhmPix
float
FWHM (in pixels) of the Psf in the science image
- candidateList
list
, optional A list of footprints/maskedImages for kernel candidates; if
None
then source detection is run.Currently supported: list of Footprints or measAlg.PsfCandidateF
- templateMaskedImage
- Returns:
- results
lsst.pipe.base.Struct
An
lsst.pipe.base.Struct
containing these fields:subtractedMaskedImage
:scienceMaskedImage
- (matchedImage + backgroundModel)matchedImage
: templateMaskedImage convolved with psfMatchingKernelpsfMatchingKernel`
: PSF matching kernelbackgroundModel
: differential background modelkernelCellSet
: SpatialCellSet used to determine PSF matching kernel
- results