lsst.ip.diffim  16.0-18-geff7d6b+2
Public Member Functions | Static Public Member Functions | Public Attributes | Static Public Attributes | List of all members
lsst.ip.diffim.imageDecorrelation.DecorrelateALKernelMapper Class Reference
Inheritance diagram for lsst.ip.diffim.imageDecorrelation.DecorrelateALKernelMapper:
lsst.ip.diffim.imageDecorrelation.DecorrelateALKernelTask lsst.ip.diffim.imageMapReduce.ImageMapper

Public Member Functions

def __init__ (self, args, kwargs)
 
def run (self, subExposure, expandedSubExposure, fullBBox, template, science, alTaskResult=None, psfMatchingKernel=None, preConvKernel=None, kwargs)
 
def computeVarianceMean (self, exposure)
 
def run (self, subExposure, expandedSubExposure, fullBBox, kwargs)
 

Static Public Member Functions

def computeCorrectedDiffimPsf (kappa, psf, svar=0.04, tvar=0.04)
 Compute the (decorrelated) difference image's new PSF. More...
 

Public Attributes

 statsControl
 

Static Public Attributes

 ConfigClass = DecorrelateALKernelConfig
 

Detailed Description

Task to be used as an ImageMapper for performing
A&L decorrelation on subimages on a grid across a A&L difference image.

This task subclasses DecorrelateALKernelTask in order to implement
all of that task's configuration parameters, as well as its `run` method.

Definition at line 393 of file imageDecorrelation.py.

Constructor & Destructor Documentation

◆ __init__()

def lsst.ip.diffim.imageDecorrelation.DecorrelateALKernelMapper.__init__ (   self,
  args,
  kwargs 
)

Definition at line 403 of file imageDecorrelation.py.

Member Function Documentation

◆ computeCorrectedDiffimPsf()

def lsst.ip.diffim.imageDecorrelation.DecorrelateALKernelTask.computeCorrectedDiffimPsf (   kappa,
  psf,
  svar = 0.04,
  tvar = 0.04 
)
staticinherited

Compute the (decorrelated) difference image's new PSF.

new_psf = psf(k) * sqrt((svar + tvar) / (svar + tvar * kappa_ft(k)**2))

Parameters
kappaA matching kernel array derived from Alard & Lupton PSF matching
psfThe uncorrected psf array of the science image (and also of the diffim)
svarAverage variance of science image used for PSF matching
tvarAverage variance of template image used for PSF matching
Returns
a 2-d numpy.array containing the new PSF

Definition at line 293 of file imageDecorrelation.py.

◆ computeVarianceMean()

def lsst.ip.diffim.imageDecorrelation.DecorrelateALKernelTask.computeVarianceMean (   self,
  exposure 
)
inherited

Definition at line 136 of file imageDecorrelation.py.

◆ run() [1/2]

def lsst.ip.diffim.imageMapReduce.ImageMapper.run (   self,
  subExposure,
  expandedSubExposure,
  fullBBox,
  kwargs 
)
inherited
Perform operation on `subExposure`.

To be implemented by subclasses. See class docstring for more
details. This method is given the `subExposure` which
is to be operated upon, and an `expandedSubExposure` which
will contain `subExposure` with additional surrounding
pixels. This allows for, for example, convolutions (which
should be performed on `expandedSubExposure`), to prevent the
returned sub-exposure from containing invalid pixels.

This method may return a new, processed sub-exposure which can
be be "stitched" back into a new resulting larger exposure
(depending on the paired, configured `ImageReducer`);
otherwise if it does not return an lsst.afw.image.Exposure, then the
`ImageReducer.config.mapper.reduceOperation`
should be set to 'none' and the result will be propagated
as-is.

Parameters
----------
subExposure : lsst.afw.image.Exposure
    the sub-exposure upon which to operate
expandedSubExposure : lsst.afw.image.Exposure
    the expanded sub-exposure upon which to operate
fullBBox : lsst.afw.geom.BoundingBox
    the bounding box of the original exposure
kwargs :
    additional keyword arguments propagated from
    `ImageMapReduceTask.run`.

Returns
-------
A `pipeBase.Struct containing the result of the `subExposure` processing,
which may itself be of any type. See above for details. If it is an
lsst.afw.image.Exposure (processed sub-exposure), then the name in the Struct
should be 'subExposure'. This is implemented here as a pass-through
example only.

Definition at line 107 of file imageMapReduce.py.

◆ run() [2/2]

def lsst.ip.diffim.imageDecorrelation.DecorrelateALKernelMapper.run (   self,
  subExposure,
  expandedSubExposure,
  fullBBox,
  template,
  science,
  alTaskResult = None,
  psfMatchingKernel = None,
  preConvKernel = None,
  kwargs 
)
Perform decorrelation operation on `subExposure`, using
`expandedSubExposure` to allow for invalid edge pixels arising from
convolutions.

This method performs A&L decorrelation on `subExposure` using
local measures for image variances and PSF. `subExposure` is a
sub-exposure of the non-decorrelated A&L diffim. It also
requires the corresponding sub-exposures of the template
(`template`) and science (`science`) exposures.

Parameters
----------
subExposure : lsst.afw.image.Exposure
    the sub-exposure of the diffim
expandedSubExposure : lsst.afw.image.Exposure
    the expanded sub-exposure upon which to operate
fullBBox : afwGeom.BoundingBox
    the bounding box of the original exposure
template : afw.Exposure
    the corresponding sub-exposure of the template exposure
science : afw.Exposure
    the corresponding sub-exposure of the science exposure
alTaskResult : pipeBase.Struct
    the result of A&L image differencing on `science` and
    `template`, importantly containing the resulting
    `psfMatchingKernel`. Can be `None`, only if
    `psfMatchingKernel` is not `None`.
psfMatchingKernel : Alternative parameter for passing the
    A&L `psfMatchingKernel` directly.
preConvKernel : If not None, then pre-filtering was applied
    to science exposure, and this is the pre-convolution
    kernel.
kwargs :
    additional keyword arguments propagated from
    `ImageMapReduceTask.run`.

Returns
-------
A `pipeBase.Struct` containing:
* `subExposure` : the result of the `subExposure` processing.
* `decorrelationKernel` : the decorrelation kernel, currently
  not used.

Notes
-----
This `run` method accepts parameters identical to those of
`ImageMapper.run`, since it is called from the
`ImageMapperTask`. See that class for more information.

Definition at line 408 of file imageDecorrelation.py.

Member Data Documentation

◆ ConfigClass

lsst.ip.diffim.imageDecorrelation.DecorrelateALKernelMapper.ConfigClass = DecorrelateALKernelConfig
static

Definition at line 400 of file imageDecorrelation.py.

◆ statsControl

lsst.ip.diffim.imageDecorrelation.DecorrelateALKernelTask.statsControl
inherited

Definition at line 131 of file imageDecorrelation.py.


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