MaskObjectsTask¶

class lsst.pipe.tasks.background.MaskObjectsTask(*args, **kwargs)¶

Bases: Task

Iterative masking of objects on an Exposure

This task makes more exhaustive object mask by iteratively doing detection and background-subtraction. The purpose of this task is to get true background removing faint tails of large objects. This is useful to get a clean sky estimate from relatively small number of visits.

We deliberately use the specified detectSigma instead of the PSF, in order to better pick up the faint wings of objects.

Methods Summary

`emptyMetadata`()	Empty (clear) the metadata for this Task and all sub-Tasks.
`findObjects`(exposure)	Iteratively find objects on an exposure
`getFullMetadata`()	Get metadata for all tasks.
`getFullName`()	Get the task name as a hierarchical name including parent task names.
`getName`()	Get the name of the task.
`getTaskDict`()	Get a dictionary of all tasks as a shallow copy.
`makeField`(doc)	Make a `lsst.pex.config.ConfigurableField` for this task.
`makeSubtask`(name, **keyArgs)	Create a subtask as a new instance as the `name` attribute of this task.
`removeObjects`(exposure[, maskPlanes])	Remove objects from exposure
`run`(exposure[, maskPlanes])	Mask objects on Exposure
`timer`(name[, logLevel])	Context manager to log performance data for an arbitrary block of code.

Methods Documentation

emptyMetadata() → None¶: Empty (clear) the metadata for this Task and all sub-Tasks.

findObjects(exposure)¶

Iteratively find objects on an exposure

Objects are masked with the DETECTED mask plane.

Parameters:

exposurelsst.afw.image.Exposure: Exposure on which to mask objects.

getFullMetadata() → TaskMetadata¶

Get metadata for all tasks.

Returns:

metadataTaskMetadata: The keys are the full task name. Values are metadata for the top-level task and all subtasks, sub-subtasks, etc.

Notes

The returned metadata includes timing information (if @timer.timeMethod is used) and any metadata set by the task. The name of each item consists of the full task name with . replaced by :, followed by . and the name of the item, e.g.:

topLevelTaskName:subtaskName:subsubtaskName.itemName

using : in the full task name disambiguates the rare situation that a task has a subtask and a metadata item with the same name.

getFullName() → str¶

Get the task name as a hierarchical name including parent task names.

Returns:

fullNamestr

The full name consists of the name of the parent task and each subtask separated by periods. For example:

The full name of top-level task “top” is simply “top”.
The full name of subtask “sub” of top-level task “top” is “top.sub”.
The full name of subtask “sub2” of subtask “sub” of top-level task “top” is “top.sub.sub2”.

getName() → str¶

Get the name of the task.

Returns:

taskNamestr: Name of the task.

See also

getFullName

getTaskDict() → Dict[str, ReferenceType[Task]]¶

Get a dictionary of all tasks as a shallow copy.

Returns:

taskDictdict: Dictionary containing full task name: task object for the top-level task and all subtasks, sub-subtasks, etc.

classmethod makeField(doc: str) → ConfigurableField¶

Make a lsst.pex.config.ConfigurableField for this task.

Parameters:

docstr: Help text for the field.

Returns:

configurableFieldlsst.pex.config.ConfigurableField: A ConfigurableField for this task.

Examples

Provides a convenient way to specify this task is a subtask of another task.

Here is an example of use:

class OtherTaskConfig(lsst.pex.config.Config):
    aSubtask = ATaskClass.makeField("brief description of task")

makeSubtask(name: str, **keyArgs: Any) → None¶

Create a subtask as a new instance as the name attribute of this task.

Parameters:

namestr

Brief name of the subtask.

keyArgs

Extra keyword arguments used to construct the task. The following arguments are automatically provided and cannot be overridden:

“config”.
“parentTask”.

Notes

The subtask must be defined by Task.config.name, an instance of ConfigurableField or RegistryField.

removeObjects(exposure, maskPlanes=None)¶

Remove objects from exposure

We interpolate over using a background model if doInterpolate is set; otherwise we simply replace everything with the median.

Parameters:

exposurelsst.afw.image.Exposure: Exposure on which to mask objects.
maskPlanesiterable of str, optional: List of mask planes to remove. DETECTED will be added as well.

run(exposure, maskPlanes=None)¶

Mask objects on Exposure

Objects are found and removed.

Parameters:

exposurelsst.afw.image.Exposure: Exposure on which to mask objects.
maskPlanesiterable of str, optional: List of mask planes to remove.

timer(name: str, logLevel: int = 10) → Iterator[None]¶

Context manager to log performance data for an arbitrary block of code.

Parameters:

namestr: Name of code being timed; data will be logged using item name: Start and End.
logLevel: A logging level constant.

Navigation

MaskObjectsTask¶