Inheritance diagram for lsst.ip.diffim.imageMapReduce.ImageReducer:

Public Member Functions
	run (self, mapperResults, exposure, **kwargs)

Static Public Attributes
	ConfigClass = ImageReducerConfig

Protected Member Functions
	_constructPsf (self, mapperResults, exposure)

Static Protected Attributes
str	_DefaultName = "ip_diffim_ImageReducer"

Detailed Description

Base class for any 'reduce' task that is to be
used as `ImageMapReduceConfig.reducer`.

Basic reduce operations are provided by the `run` method
of this class, to be selected by its config.

Definition at line 181 of file imageMapReduce.py.

Member Function Documentation

◆ _constructPsf()

lsst.ip.diffim.imageMapReduce.ImageReducer._constructPsf	(	self,
		mapperResults,
		exposure )

protected

Construct a CoaddPsf based on PSFs from individual subExposures

Currently uses (and returns) a CoaddPsf. TBD if we want to
create a custom subclass of CoaddPsf to differentiate it.

Parameters
----------
mapperResults : `list`
    list of `pipeBase.Struct` returned by `ImageMapper.run`.
    For this to work, each element of `mapperResults` must contain
    a `subExposure` element, from which the component Psfs are
    extracted (thus the reducerTask cannot have
    `reduceOperation = 'none'`.
exposure : `lsst.afw.image.Exposure`
    the original exposure which is used here solely for its
    bounding-box and WCS.

Returns
-------
psf : `lsst.meas.algorithms.CoaddPsf`
    A psf constructed from the PSFs of the individual subExposures.

Definition at line 325 of file imageMapReduce.py.

◆ run()

lsst.ip.diffim.imageMapReduce.ImageReducer.run	(		self,
			mapperResults,
			exposure,
		**	kwargs )

Reduce a list of items produced by `ImageMapper`.

Either stitch the passed `mapperResults` list
together into a new Exposure (default) or pass it through
(if `self.config.reduceOperation` is 'none').

If `self.config.reduceOperation` is not 'none', then expect
that the `pipeBase.Struct`s in the `mapperResults` list
contain sub-exposures named 'subExposure', to be stitched back
into a single Exposure with the same dimensions, PSF, and mask
as the input `exposure`. Otherwise, the `mapperResults` list
is simply returned directly.

Parameters
----------
mapperResults : `list`
    list of `lsst.pipe.base.Struct` returned by `ImageMapper.run`.
exposure : `lsst.afw.image.Exposure`
    the original exposure which is cloned to use as the
    basis for the resulting exposure (if
    ``self.config.mapper.reduceOperation`` is not 'None')
kwargs :
    additional keyword arguments propagated from
    `ImageMapReduceTask.run`.

Returns
-------
A `lsst.pipe.base.Struct` containing either an `lsst.afw.image.Exposure`
(named 'exposure') or a list (named 'result'),
depending on `config.reduceOperation`.

Notes
-----
1. This currently correctly handles overlapping sub-exposures.
   For overlapping sub-exposures, use `config.reduceOperation='average'`.
2. This correctly handles varying PSFs, constructing the resulting
   exposure's PSF via CoaddPsf (DM-9629).

Known issues

1. To be done: correct handling of masks (nearly there)
2. This logic currently makes *two* copies of the original exposure
   (one here and one in `mapper.run()`). Possibly of concern
   for large images on memory-constrained systems.

Definition at line 191 of file imageMapReduce.py.

Member Data Documentation

◆ _DefaultName

str lsst.ip.diffim.imageMapReduce.ImageReducer._DefaultName = "ip_diffim_ImageReducer"

staticprotected

Definition at line 189 of file imageMapReduce.py.

◆ ConfigClass

lsst.ip.diffim.imageMapReduce.ImageReducer.ConfigClass = ImageReducerConfig

static

Definition at line 188 of file imageMapReduce.py.

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

python/lsst/ip/diffim/imageMapReduce.py

Public Member Functions

Static Public Attributes

Protected Member Functions