lsst.ip.diffim  15.0-9-g15da764+5
Public Member Functions | Public Attributes | Static Public Attributes | List of all members
lsst.ip.diffim.imageDecorrelation.DecorrelateALKernelSpatialTask Class Reference

Decorrelate the effect of convolution by Alard-Lupton matching kernel in image difference. More...

Inheritance diagram for lsst.ip.diffim.imageDecorrelation.DecorrelateALKernelSpatialTask:

Public Member Functions

def __init__ (self, args, kwargs)
 
def computeVarianceMean (self, exposure)
 
def run (self, scienceExposure, templateExposure, subtractedExposure, psfMatchingKernel, spatiallyVarying=True, preConvKernel=None)
 Perform decorrelation of an image difference exposure. More...
 

Public Attributes

 statsControl
 

Static Public Attributes

 ConfigClass = DecorrelateALKernelSpatialConfig
 

Detailed Description

Decorrelate the effect of convolution by Alard-Lupton matching kernel in image difference.

Contents

Description

Pipe-task that removes the neighboring-pixel covariance in an image difference that are added when the template image is convolved with the Alard-Lupton PSF matching kernel.

This task is a simple wrapper around LSST_task_documentation, which takes a spatiallyVarying parameter in its run method. If it is False, then it simply calls the run method of LSST_task_documentation. If it is True, then it uses the LSST_task_documentation framework to break the exposures into subExposures on a grid, and performs the run method of LSST_task_documentation on each subExposure. This enables it to account for spatially-varying PSFs and noise in the exposures when performing the decorrelation.

Task initialization

Create the image decorrelation Task

Parameters
----------
args :
    arguments to be passed to
    `lsst.pipe.base.task.Task.__init__`
kwargs :
    additional keyword arguments to be passed to
    `lsst.pipe.base.task.Task.__init__`

Invoking the Task

Perform decorrelation of an image difference exposure. Decorrelates the diffim due to the convolution of the templateExposure with the A&L psfMatchingKernel. If spatiallyVarying is True, it utilizes the spatially varying matching kernel via the imageMapReduce framework to perform spatially-varying decorrelation on a grid of subExposures.

Parameters

scienceExposure : lsst.afw.image.Exposure the science Exposure used for PSF matching templateExposure : lsst.afw.image.Exposure the template Exposure used for PSF matching subtractedExposure : lsst.afw.image.Exposure the subtracted Exposure produced by ip_diffim.ImagePsfMatchTask.subtractExposures() psfMatchingKernel : an (optionally spatially-varying) PSF matching kernel produced by ip_diffim.ImagePsfMatchTask.subtractExposures() spatiallyVarying : bool if True, perform the spatially-varying operation preConvKernel : lsst.meas.algorithms.Psf if not none, the scienceExposure has been pre-filtered with this kernel. (Currently this option is experimental.)

Returns

a pipeBase.Struct containing:

Configuration parameters

See DecorrelateALKernelSpatialConfig

Debug variables

This task has no debug variables

Example of using DecorrelateALKernelSpatialTask

This task has no standalone example, however it is applied as a subtask of pipe.tasks.imageDifference.ImageDifferenceTask. There is also an example of its use in tests/testImageDecorrelation.py.

Definition at line 526 of file imageDecorrelation.py.

Constructor & Destructor Documentation

◆ __init__()

def lsst.ip.diffim.imageDecorrelation.DecorrelateALKernelSpatialTask.__init__ (   self,
  args,
  kwargs 
)
Create the image decorrelation Task

Parameters
----------
args :
    arguments to be passed to
    `lsst.pipe.base.task.Task.__init__`
kwargs :
    additional keyword arguments to be passed to
    `lsst.pipe.base.task.Task.__init__`

Definition at line 581 of file imageDecorrelation.py.

Member Function Documentation

◆ computeVarianceMean()

def lsst.ip.diffim.imageDecorrelation.DecorrelateALKernelSpatialTask.computeVarianceMean (   self,
  exposure 
)
Compute the mean of the variance plane of `exposure`.

Definition at line 600 of file imageDecorrelation.py.

◆ run()

def lsst.ip.diffim.imageDecorrelation.DecorrelateALKernelSpatialTask.run (   self,
  scienceExposure,
  templateExposure,
  subtractedExposure,
  psfMatchingKernel,
  spatiallyVarying = True,
  preConvKernel = None 
)

Perform decorrelation of an image difference exposure.

Decorrelates the diffim due to the convolution of the templateExposure with the A&L psfMatchingKernel. If spatiallyVarying is True, it utilizes the spatially varying matching kernel via the imageMapReduce framework to perform spatially-varying decorrelation on a grid of subExposures.

Parameters

scienceExposure : lsst.afw.image.Exposure the science Exposure used for PSF matching templateExposure : lsst.afw.image.Exposure the template Exposure used for PSF matching subtractedExposure : lsst.afw.image.Exposure the subtracted Exposure produced by ip_diffim.ImagePsfMatchTask.subtractExposures() psfMatchingKernel : an (optionally spatially-varying) PSF matching kernel produced by ip_diffim.ImagePsfMatchTask.subtractExposures() spatiallyVarying : bool if True, perform the spatially-varying operation preConvKernel : lsst.meas.algorithms.Psf if not none, the scienceExposure has been pre-filtered with this kernel. (Currently this option is experimental.)

Returns

a pipeBase.Struct containing:

  • correctedExposure: the decorrelated diffim

Definition at line 610 of file imageDecorrelation.py.

Member Data Documentation

◆ ConfigClass

lsst.ip.diffim.imageDecorrelation.DecorrelateALKernelSpatialTask.ConfigClass = DecorrelateALKernelSpatialConfig
static

Definition at line 578 of file imageDecorrelation.py.

◆ statsControl

lsst.ip.diffim.imageDecorrelation.DecorrelateALKernelSpatialTask.statsControl

Definition at line 595 of file imageDecorrelation.py.


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