Inheritance diagram for lsst.pipe.tasks.snapCombine.SnapCombineTask:

Public Member Functions
	__init__ (self, args, *kwargs)

	run (self, snap0, snap1)

Static Public Attributes
	ConfigClass = SnapCombineConfig

Protected Member Functions
	_add_snaps (self, snap0, snap1)

	_merge_visit_info (self, info0, info1)

Static Protected Attributes
str	_DefaultName = "snapCombine"

Detailed Description

Combine two snaps into a single visit image.

Definition at line 40 of file snapCombine.py.

Constructor & Destructor Documentation

◆ init()

lsst.pipe.tasks.snapCombine.SnapCombineTask.__init__	(		self,
		*	args,
		**	kwargs )

Definition at line 47 of file snapCombine.py.

    def __init__(self, *args, **kwargs):
        pipeBase.Task.__init__(self, *args, **kwargs)
 

Member Function Documentation

◆ _add_snaps()

lsst.pipe.tasks.snapCombine.SnapCombineTask._add_snaps	(	self,
		snap0,
		snap1 )

protected

Add two snap exposures together, returning a new exposure.

Parameters
----------
snap0 : `lsst.afw.image.Exposure`
    Snap exposure 0.
snap1 : `lsst.afw.image.Exposure`
    Snap exposure 1.

Returns
-------
combined : `lsst.afw.image.Exposure`
    Combined exposure.

Definition at line 76 of file snapCombine.py.

    def _add_snaps(self, snap0, snap1):
        """Add two snap exposures together, returning a new exposure.
 
        Parameters
        ----------
        snap0 : `lsst.afw.image.Exposure`
            Snap exposure 0.
        snap1 : `lsst.afw.image.Exposure`
            Snap exposure 1.
 
        Returns
        -------
        combined : `lsst.afw.image.Exposure`
            Combined exposure.
        """
        combined = snap0.Factory(snap0, True)
        combined.maskedImage.set(0)
 
        weights = combined.maskedImage.image.Factory(combined.maskedImage.getBBox())
        weight = 1.0
        bad_mask = afwImage.Mask.getPlaneBitMask(self.config.bad_mask_planes)
        addToCoadd(combined.maskedImage, weights, snap0.maskedImage, bad_mask, weight)
        addToCoadd(combined.maskedImage, weights, snap1.maskedImage, bad_mask, weight)
 
        # pre-scaling the weight map instead of post-scaling the combined.maskedImage saves a bit of time
        # because the weight map is a simple Image instead of a MaskedImage
        weights *= 0.5  # so result is sum of both images, instead of average
        combined.maskedImage /= weights
        setCoaddEdgeBits(combined.maskedImage.getMask(), weights)
 
        combined.info.setVisitInfo(self._merge_visit_info(snap0.visitInfo, snap1.visitInfo))
 
        return combined
 

◆ _merge_visit_info()

lsst.pipe.tasks.snapCombine.SnapCombineTask._merge_visit_info	(	self,
		info0,
		info1 )

protected

Merge the visitInfo values from the two exposures.

In particular:
 * id will be the id of snap 0.
 * date will be the average of the dates.
 * exposure time will be the sum of the times.

Parameters
----------
info0, info1 : `lsst.afw.image.VisitInfo`
    Metadata to combine.

Returns
-------
info : `lsst.afw.image.VisitInfo`
    Combined metadata.

Definition at line 110 of file snapCombine.py.

    def _merge_visit_info(self, info0, info1):
        """Merge the visitInfo values from the two exposures.
 
        In particular:
         * id will be the id of snap 0.
         * date will be the average of the dates.
         * exposure time will be the sum of the times.
 
        Parameters
        ----------
        info0, info1 : `lsst.afw.image.VisitInfo`
            Metadata to combine.
 
        Returns
        -------
        info : `lsst.afw.image.VisitInfo`
            Combined metadata.
 
        """
        time = info0.exposureTime + info1.exposureTime
        date = (info0.date.get() + info1.date.get()) / 2.0
        result = info0.copyWith(exposureTime=time,
                                date=dafBase.DateTime(date)
                                )
        return result

◆ run()

lsst.pipe.tasks.snapCombine.SnapCombineTask.run	(	self,
		snap0,
		snap1 )

Combine two snaps, returning the combined image.

Parameters
----------
snap0 : `lsst.afw.image.Exposure`
    Snapshot exposure 0.
snap1 : `lsst.afw.image.Exposure`
    Snapshot exposure 1.

Returns
-------
result : `lsst.pipe.base.Struct`
    Results as a struct with attributes:

    ``exposure``
        Snap-combined exposure.

Definition at line 51 of file snapCombine.py.

    def run(self, snap0, snap1):
        """Combine two snaps, returning the combined image.
 
        Parameters
        ----------
        snap0 : `lsst.afw.image.Exposure`
            Snapshot exposure 0.
        snap1 : `lsst.afw.image.Exposure`
            Snapshot exposure 1.
 
        Returns
        -------
        result : `lsst.pipe.base.Struct`
            Results as a struct with attributes:
 
            ``exposure``
                Snap-combined exposure.
        """
        self.log.info("Merging two snaps with exposure ids: %s, %s", snap0.visitInfo.id, snap1.visitInfo.id)
        combined = self._add_snaps(snap0, snap1)
 
        return pipeBase.Struct(
            exposure=combined,
        )
 

Member Data Documentation

◆ _DefaultName

str lsst.pipe.tasks.snapCombine.SnapCombineTask._DefaultName = "snapCombine"

staticprotected

Definition at line 45 of file snapCombine.py.

◆ ConfigClass

lsst.pipe.tasks.snapCombine.SnapCombineTask.ConfigClass = SnapCombineConfig

static

Definition at line 44 of file snapCombine.py.

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

/j/snowflake/release/lsstsw/stack/lsst-scipipe-8.0.0/Linux64/pipe_tasks/g3e7165581c+1687b54203/python/lsst/pipe/tasks/snapCombine.py

Public Member Functions

Static Public Attributes

Protected Member Functions

Static Protected Attributes