AlardLuptonSubtractTask¶
- class lsst.ip.diffim.AlardLuptonSubtractTask(**kwargs)¶
Bases:
PipelineTask
Compute the image difference of a science and template image using the Alard & Lupton (1998) algorithm.
Attributes Summary
Methods Summary
Empty (clear) the metadata for this Task and all sub-Tasks.
finalize
(template, science, difference, kernel)Decorrelate the difference image to undo the noise correlations caused by convolution.
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.
getName
()Get the name of the task.
Return resource configuration for this task.
Get the schemas generated by this task.
Get a dictionary of all tasks as a shallow copy.
makeField
(doc)Make a
lsst.pex.config.ConfigurableField
for this task.makeSubtask
(name, **keyArgs)Create a subtask as a new instance as the
name
attribute of this task.run
(template, science, sources)PSF match, subtract, and decorrelate two images.
runConvolveScience
(template, science, sources)Convolve the science image with a PSF-matching kernel and subtract the template image.
runConvolveTemplate
(template, science, sources)Convolve the template image with a PSF-matching kernel and subtract from the science image.
runQuantum
(butlerQC, inputRefs, outputRefs)Method to do butler IO and or transforms to provide in memory objects for tasks run method
timer
(name[, logLevel])Context manager to log performance data for an arbitrary block of code.
Attributes Documentation
Methods Documentation
- finalize(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?
- template
- Returns:
- correctedExposure
lsst.afw.image.ExposureF
The decorrelated image difference.
- correctedExposure
- 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
- getResourceConfig() ResourceConfig | None ¶
Return resource configuration for this task.
- Returns:
- Object of type
ResourceConfig
orNone
if resource - configuration is not defined for this task.
- Object of type
- 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.
- 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
- 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")
- 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
.
- run(template, science, sources)¶
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.
- template
- 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.
- results
- 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
- runConvolveScience(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.
- template
- 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.
- results
- runConvolveTemplate(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.
- template
- 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.
- results
- runQuantum(butlerQC: ButlerQuantumContext, inputRefs: InputQuantizedConnection, outputRefs: OutputQuantizedConnection) None ¶
Method to do butler IO and or transforms to provide in memory objects for tasks run method
- Parameters:
- butlerQC
ButlerQuantumContext
A butler which is specialized to operate in the context of a
lsst.daf.butler.Quantum
.- inputRefs
InputQuantizedConnection
Datastructure whose attribute names are the names that identify connections defined in corresponding
PipelineTaskConnections
class. The values of these attributes are thelsst.daf.butler.DatasetRef
objects associated with the defined input/prerequisite connections.- outputRefs
OutputQuantizedConnection
Datastructure whose attribute names are the names that identify connections defined in corresponding
PipelineTaskConnections
class. The values of these attributes are thelsst.daf.butler.DatasetRef
objects associated with the defined output connections.
- butlerQC