lsst.ip.diffim¶

The lsst.ip.diffim module provides algorithms for astronomical image differencing.

Using lsst.ip.diffim¶

Contributing¶

lsst.ip.diffim is developed at https://github.com/lsst/ip_diffim. You can find Jira issues for this module under the ip_diffim component.

Task reference¶

Tasks¶

FractionDiaSourcesToSciSourcesMetricTask: Task that computes the ratio of difference image sources to science sources in an image, visit, etc.
NumberSciSourcesMetricTask: Task that computes the number of cataloged science sources.

Configurations¶

No topics.

Python API reference¶

lsst.ip.diffim Package¶

Functions¶

`AssessSpatialKernelVisitorF`
`BuildSingleKernelVisitorF`
`BuildSpatialKernelVisitorF`
`ImageStatisticsF`
`KernelCandidateDetectionF`
`KernelCandidateF`
`KernelSumVisitorF`
`applyDcr`(image, dcr[, useInverse, …])	Shift an image along the X and Y directions.
`backgroundSubtract`(config, maskedImages)	Subtract the background from masked images.
`calculateDcr`(visitInfo, wcs, filterInfo, …)	Calculate the shift in pixels of an exposure due to DCR.
`calculateImageParallacticAngle`(visitInfo, wcs)	Calculate the total sky rotation angle of an exposure.
`convolveAndSubtract`(args, *kwargs)	Overloaded function.
`generateAlardLuptonBasisList`(config[, …])	Generate an Alard-Lupton kernel basis list based upon the Config and the input FWHM of the science and template images.
`makeAlardLuptonBasisList`(halfWidth, nGauss, …)
`makeAssessSpatialKernelVisitor`(…)
`makeBuildSingleKernelVisitor`(args, *kwargs)	Overloaded function.
`makeBuildSpatialKernelVisitor`(basisList, …)
`makeCentralDifferenceMatrix`(width, height, …)
`makeDeltaFunctionBasisList`(width, height)
`makeForwardDifferenceMatrix`(width, height, …)
`makeKernelBasisList`(config[, targetFwhmPix, …])	Generate the delta function or Alard-Lupton kernel bases depending on the Config.
`makeKernelCandidate`(args, *kwargs)	Overloaded function.
`makeKernelPcaVisitor`(imagePca)
`makeKernelSumVisitor`(ps)
`makeRegularizationMatrix`(ps)
`renormalizeKernelList`(kernelListIn)
`sourceToFootprintList`(candidateInList, …)	Convert a list of sources for the PSF-matching Kernel to Footprints.
`writeKernelCellSet`(kernelCellSet, …)	TODO: DM-17458

Classes¶

`ClassificationDipoleConfig`	Configuration for classification of detected diaSources as dipole or not
`ClassificationDipolePlugin`(config, name, …)	A plugin to classify whether a diaSource is a dipole.
`DcrModel`(modelImages[, filterInfo, psf, …])	A model of the true sky after correcting chromatic effects.
`DecorrelateALKernelConfig`	Configuration parameters for the DecorrelateALKernelTask
`DecorrelateALKernelMapReduceConfig`	Configuration parameters for the ImageMapReduceTask to direct it to use DecorrelateALKernelMapper as its mapper for A&L decorrelation.
`DecorrelateALKernelMapper`(args, *kwargs)	Task to be used as an ImageMapper for performing A&L decorrelation on subimages on a grid across a A&L difference image.
`DecorrelateALKernelSpatialConfig`	Configuration parameters for the DecorrelateALKernelSpatialTask.
`DecorrelateALKernelSpatialTask`(args, *kwargs)	Decorrelate the effect of convolution by Alard-Lupton matching kernel in image difference
`DecorrelateALKernelTask`(args, *kwargs)	Decorrelate the effect of convolution by Alard-Lupton matching kernel in image difference
`DetectionConfig`	Configuration for detecting sources on images for building a PSF-matching kernel
`DiaCatalogSourceSelectorConfig`
`DiaCatalogSourceSelectorTask`(**kwargs)	A task that selects sources for Kernel candidates.
`DiaSourceAnalyst`(config)
`DiaSourceAnalystConfig`
`DipoleAnalysis`()	Functor class that provides (S/N, position, orientation) of measured dipoles
`DipoleCentroidControl`
`DipoleDeblender`()	Functor to deblend a source as a dipole, and return a new source with deblended footprints.
`DipoleFitAlgorithm`(diffim[, posImage, negImage])	Fit a dipole model using an image difference.
`DipoleFitPlugin`(config, name, schema, metadata)	A single frame measurement plugin that fits dipoles to all merged (two-peak) `diaSources`.
`DipoleFitPluginConfig`	Configuration for DipoleFitPlugin
`DipoleFitTask`(schema[, algMetadata])	A task that fits a dipole to a difference image, with an optional separate detection image.
`DipoleFitTaskConfig`	Measurement of detected diaSources as dipoles
`DipoleFluxControl`
`DipoleMeasurementConfig`	Measurement of detected diaSources as dipoles
`DipoleMeasurementTask`(schema[, algMetadata])	Measurement of Sources, specifically ones from difference images, for characterization as dipoles
`FindSetBitsU`
`GetCalexpAsTemplateConfig`
`GetCalexpAsTemplateTask`([config, name, …])	Subtask to retrieve calexp of the same ccd number as the science image SensorRef for use as an image difference template.
`GetCoaddAsTemplateConfig`
`GetCoaddAsTemplateTask`([config, name, …])	Subtask to retrieve coadd for use as an image difference template.
`ImageMapReduceConfig`	Configuration parameters for the ImageMapReduceTask
`ImageMapReduceTask`(args, *kwargs)	Split an Exposure into subExposures (optionally on a grid) and perform the same operation on each.
`ImageMapper`([config, name, parentTask, log])	Abstract base class for any task that is to be used as `ImageMapReduceConfig.mapper`.
`ImageMapperConfig`	Configuration parameters for ImageMapper
`ImagePsfMatchConfig`	Configuration for image-to-image Psf matching.
`ImagePsfMatchTask`(args, *kwargs)	Psf-match two MaskedImages or Exposures using the sources in the images.
`ImageReducer`([config, name, parentTask, log])	Base class for any ‘reduce’ task that is to be used as `ImageMapReduceConfig.reducer`.
`ImageReducerConfig`	Configuration parameters for the ImageReducer
`ImageStatisticsD`
`ImageStatisticsI`
`KernelCandidateQa`(nKernelSpatial)	Quality Assessment class for Kernel Candidates
`KernelPcaD`
`KernelPcaVisitorF`
`KernelSolution`
`MaskedKernelSolutionF`
`ModelPsfMatchConfig`	Configuration for model-to-model Psf matching
`ModelPsfMatchTask`(args, *kwargs)	Matching of two model Psfs, and application of the Psf-matching kernel to an input Exposure
`NaiveDipoleCentroid`
`NaiveDipoleFlux`
`NbasisEvaluator`(psfMatchConfig, …)	A functor to evaluate the Bayesian Information Criterion for the number of basis sets going into the kernel fitting
`PsfDipoleFlux`
`PsfDipoleFluxControl`
`PsfMatchConfig`	Base configuration for Psf-matching
`PsfMatchConfigAL`	The parameters specific to the “Alard-Lupton” (sum-of-Gaussian) Psf-matching basis
`PsfMatchConfigDF`	The parameters specific to the delta-function (one basis per-pixel) Psf-matching basis
`PsfMatchTask`(args, *kwargs)	Base class for Psf Matching; should not be called directly
`RegularizedKernelSolutionF`
`SnapPsfMatchConfig`
`SnapPsfMatchConfigAL`	Sum-of-Gaussian (Alard-Lupton) Psf-matching config optimized for snap subtraction
`SnapPsfMatchConfigDF`	Delta-function Psf-matching config optimized for snap subtraction
`SnapPsfMatchTask`(args, *kwargs)	Image-based Psf-matching of two subsequent snaps from the same visit
`SourceFlagChecker`(sources[, badFlags])	Functor class to check whether a diaSource has flags set that should cause it to be labeled bad.
`SpatialKernelSolution`
`StaticKernelSolutionF`
`ZogyConfig`	Configuration parameters for the ZogyTask
`ZogyImagePsfMatchConfig`	Config for the ZogyImagePsfMatchTask
`ZogyImagePsfMatchTask`(args, *kwargs)	Task to perform Zogy PSF matching and image subtraction.
`ZogyMapReduceConfig`	Config to be passed to ImageMapReduceTask
`ZogyMapper`(args, *kwargs)	Task to be used as an ImageMapper for performing ZOGY image subtraction on a grid of subimages.
`ZogyTask`([templateExposure, …])	Task to perform ZOGY proper image subtraction.

Class Inheritance Diagram¶

lsst.ip.diffim.metrics Module¶

Classes¶

`NumberSciSourcesMetricTask`(**kwargs)	Task that computes the number of cataloged science sources.
`NumberSciSourcesMetricConfig`
`FractionDiaSourcesToSciSourcesMetricTask`(…)	Task that computes the ratio of difference image sources to science sources in an image, visit, etc.
`FractionDiaSourcesToSciSourcesMetricConfig`