Winter2013ImageDifferenceTask¶
Python API summary¶
from lsst.pipe.tasks.imageDifference import Winter2013ImageDifferenceTask
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class
Winter2013ImageDifferenceTask !Image difference Task used in the Winter 2013 data challege. Enables testing the effects of registration shifts and scatter
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attribute
config Access configuration fields and retargetable subtasks.
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method
run PSF matches, subtract two images and perform detection on the difference image
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method
runDataRef Subtract an image from a template coadd and measure the result
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See also
See the Winter2013ImageDifferenceTask API reference for complete details.
Retargetable subtasks¶
applyApCorr¶
- Default
lsst.meas.base.applyApCorr.ApplyApCorrTask- Field type
ConfigurableField
Subtask to apply aperture corrections
astrometer¶
- Default
lsst.meas.astrom.astrometry.AstrometryTask- Field type
ConfigurableField
astrometry task; used to match sources to reference objects, but not to fit a WCS
decorrelate¶
- Default
lsst.ip.diffim.imageDecorrelation.DecorrelateALKernelSpatialTask- Field type
ConfigurableField
Decorrelate effects of A&L kernel convolution on image difference, only if doSubtract is True. If this option is enabled, then detection.thresholdValue should be set to 5.0 (rather than the default of 5.5).
detection¶
- Default
lsst.meas.algorithms.detection.SourceDetectionTask- Field type
ConfigurableField
Low-threshold detection for final measurement
forcedMeasurement¶
- Default
lsst.meas.base.forcedMeasurement.ForcedMeasurementTask- Field type
ConfigurableField
Subtask to force photometer PVI at diaSource location.
getTemplate¶
- Default
lsst.ip.diffim.getTemplate.GetCoaddAsTemplateTask- Field type
ConfigurableField
Subtask to retrieve template exposure and sources
measurement¶
- Default
lsst.ip.diffim.dipoleFitTask.DipoleFitTask- Field type
ConfigurableField
Enable updated dipole fitting method
refObjLoader¶
- Default
lsst.meas.algorithms.loadIndexedReferenceObjects.LoadIndexedReferenceObjectsTask- Field type
ConfigurableField
reference object loader
register¶
- Default
lsst.pipe.tasks.registerImage.RegisterTask- Field type
ConfigurableField
Task to enable image-to-image image registration (warping)
scaleVariance¶
- Default
lsst.pipe.tasks.scaleVariance.ScaleVarianceTask- Field type
ConfigurableField
Subtask to rescale the variance of the template to the statistically expected level
sourceSelector¶
- Default
lsst.meas.algorithms.objectSizeStarSelector.ObjectSizeStarSelectorTask- Field type
ConfigurableField
Source selection algorithm
subtract¶
- Default
'al'- Field type
- Single-selection
RegistryField - Choices
'al'lsst.ip.diffim.imagePsfMatch.ImagePsfMatchTask'zogy'lsst.ip.diffim.zogy.ZogyImagePsfMatchTask
Subtraction Algorithm
Configuration fields¶
coaddName¶
coadd name: typically one of deep, goodSeeing, or dcr
connections¶
- Data type
lsst.pipe.base.config.Connections- Field type
ConfigField
Configurations describing the connections of the PipelineTask to datatypes
controlStepSize¶
What step size (every Nth one) to select a control sample from the kernelSources
convolveTemplate¶
Which image gets convolved (default = template)
diaSourceMatchRadius¶
Match radius (in arcseconds) for DiaSource to Source association
doAddCalexpBackground¶
Add background to calexp before processing it. Useful as ipDiffim does background matching.
doAddMetrics¶
Add columns to the source table to hold analysis metrics?
doDecorrelation¶
Perform diffim decorrelation to undo pixel correlation due to A&L kernel convolution (AL only)? If True, also update the diffim PSF.
doForcedMeasurement¶
Force photometer diaSource locations on PVI?
doMatchSources¶
Match diaSources with input calexp sources and ref catalog sources
doMerge¶
Merge positive and negative diaSources with grow radius set by growFootprint
doPreConvolve¶
Convolve science image by its PSF before PSF-matching (AL only). The difference image becomes a likelihood image.
doScaleDiffimVariance¶
Scale variance of the diffim before PSF matching. You may do either this or template variance scaling, or neither. (Doing both is a waste of CPU.)
doScaleTemplateVariance¶
Scale variance of the template before PSF matching
doSelectDcrCatalog¶
Select stars of extreme color as part of the control sample (AL only)
doSelectSources¶
Select stars to use for kernel fitting (AL only)
doSelectVariableCatalog¶
Select stars that are variable to be part of the control sample (AL only)
doSpatiallyVarying¶
Perform A&L decorrelation on a grid across the image in order to allow for spatial variations. Zogy does not use this option.
doUseRegister¶
Re-compute astrometry on the template. Use image-to-image registration to align template with science image (AL only).
doWriteMatchedExp¶
Write warped and PSF-matched template coadd exposure?
growFootprint¶
Grow positive and negative footprints by this amount before merging
kernelSourcesFromRef¶
Select sources to measure kernel from reference catalog if True, template if false
requiredTemplateFraction¶
Do not attempt to run task if template covers less than this fraction of pixels.Setting to 0 will always attempt image subtraction
saveMetadata¶
Flag to enable/disable metadata saving for a task, enabled by default.
templateSipOrder¶
Sip Order for fitting the Template Wcs (default is too high, overfitting)
useGaussianForPreConvolution¶
Use a simple gaussian PSF model for pre-convolution (else use fit PSF)? Ignored if doPreConvolve false.
useScoreImageDetection¶
Calculate and detect sources on the Zogy score image (Zogy only).
winter2013WcsRms¶
Perturb stars going into RegisterTask by this amount