SourceDeblendTask¶
SourceDeblendTask splits blended sources into individual sources.
Processing summary¶
SourceDeblendTask performs housekeeping work — updating table
schemas and extracting the PSF from the input image — then delegates
to lsst.meas.deblender.deblend to perform deblending.
The task has no return value; the input
SourceCatalog is modified in-place.
Python API summary¶
from lsst.meas.deblender.sourceDeblendTask import SourceDeblendTask
-
class
SourceDeblendTask(schema, peakSchema=None, **kwargs) Split blended sources into individual sources
...
- attributeconfig
Access configuration fields and retargetable subtasks.
See also
See the SourceDeblendTask API reference for complete details.
Retargetable subtasks¶
No subtasks.
Configuration fields¶
assignStrayFlux¶
Assign stray flux (not claimed by any child in the deblender) to deblend children.
catchFailures¶
If True, catch exceptions thrown by the deblender, log them, and set a flag on the parent, instead of letting them propagate up.
ciDeblendChildRange¶
Only deblend parent Footprints with a number of peaks in the (inclusive) range indicated.If useCiLimits==False then this parameter is ignored.
ciNumParentsToDeblend¶
Only use the first ciNumParentsToDeblend parent footprints with a total peak count within ciDebledChildRange. If useCiLimits==False then this parameter is ignored.
clipStrayFluxFraction¶
When splitting stray flux, clip fractions below this value to zero.
edgeHandling¶
- Default
'ramp'- Field type
strChoiceField(optional)- Choices
'clip'Clip the template at the edge AND the mirror of the edge.
'ramp'Ramp down flux at the image edge by the PSF
'noclip'Ignore the edge when building the symmetric template.
NoneField is optional
What to do when a peak to be deblended is close to the edge of the image
maskLimits¶
Mask planes with the corresponding limit on the fraction of masked pixels. Sources violating this limit will not be deblended.
maskPlanes¶
Mask planes to ignore when performing statistics
maxFootprintArea¶
Maximum area for footprints before they are ignored as large; non-positive means no threshold applied
maxFootprintSize¶
Maximum linear dimension for footprints before they are ignored as large; non-positive means no threshold applied
maxNumberOfPeaks¶
Only deblend the brightest maxNumberOfPeaks peaks in the parent (<= 0: unlimited)
maxTempDotProd¶
If the dot product between two templates is larger than this value, we consider them to be describing the same object (i.e. they are degenerate). If one of the objects has been labeled as a PSF it will be removed, otherwise the template with the lowest value will be removed.
medianSmoothTemplate¶
Apply a smoothing filter to all of the template images
minFootprintAxisRatio¶
Minimum axis ratio for footprints before they are ignored as large; non-positive means no threshold applied
notDeblendedMask¶
Mask name for footprints not deblended, or None
propagateAllPeaks¶
Guarantee that all peaks produce a child source.
psfChisq1¶
Chi-squared per DOF cut for deciding a source is a PSF during deblending (un-shifted PSF model)
psfChisq2¶
Chi-squared per DOF cut for deciding a source is PSF during deblending (shifted PSF model)
psfChisq2b¶
Chi-squared per DOF cut for deciding a source is a PSF during deblending (shifted PSF model #2)
removeDegenerateTemplates¶
Try to remove similar templates?
strayFluxRule¶
- Default
'trim'- Field type
strChoiceField(optional)- Choices
'r-to-peak'~ 1/(1+R^2) to the peak
'r-to-footprint'~ 1/(1+R^2) to the closest pixel in the footprint. CAUTION: this can be computationally expensive on large footprints!
'nearest-footprint'Assign 100% to the nearest footprint (using L-1 norm aka Manhattan distance)
'trim'Shrink the parent footprint to pixels that are not assigned to children
NoneField is optional
How to split flux among peaks
strayFluxToPointSources¶
- Default
'necessary'- Field type
strChoiceField(optional)- Choices
'necessary'When there is not an extended object in the footprint
'always'Always
'never'Never; stray flux will not be attributed to any deblended child if the deblender thinks all peaks look like point sources
NoneField is optional
When the deblender should attribute stray flux to point sources
tinyFootprintSize¶
- Default
2- Field type
- Range
[2,inf)
Footprints smaller in width or height than this value will be ignored; minimum of 2 due to PSF gradient calculation.
useCiLimits¶
Limit the number of sources deblended for CI to prevent long build times
weightTemplates¶
If true, a least-squares fit of the templates will be done to the full image. The templates will be re-weighted based on this fit.