AmplifierIsolator¶
- class lsst.afw.cameraGeom.AmplifierIsolator(amplifier, parent_bbox, parent_detector)¶
Bases:
object
A class that can extracts single-amplifier subimages from trimmed or untrimmed assembled images and transforms them to a particular orientation and offset.
Callers who have a in-memory assembled
lsst.afw.image.Exposure
should generally just use theapply
class method. Other methods can be used to implement subimage loads of on on-disk images (e.g. formatter classes inobs_base
) or obtain subsets from other image classes.- Parameters:
- amplifier
Amplifier
Amplifier object that identifies the amplifier to load and sets the orientation and offset of the returned subimage.
- parent_bbox
lsst.geom.Box2I
Bounding box of the assembled parent image. This must be equal to either
parent_detector.getBBox()
orparent_detector.getRawBBox()
; which one is used to determine whether the parent image (and hence the amplifier subimages) is trimmed.- parent_detector
Detector
Detector object that describes the parent image.
- amplifier
Attributes Summary
The bounding box of the target amplifier in the parent image (
lsst.geom.Box2I
).Methods Summary
apply
(parent_exposure, amplifier)Obtain a single-amplifier
lsst.afw.image.Exposure
subimage that masquerades as full-detector image for a single-amp detector.Create a single-amplifier detector that describes the transformed subimage.
transform_subimage
(subimage)Transform an already-extracted subimage to match the orientation and offset of the target amplifier.
Attributes Documentation
- subimage_bbox¶
The bounding box of the target amplifier in the parent image (
lsst.geom.Box2I
).
Methods Documentation
- classmethod apply(parent_exposure, amplifier)¶
Obtain a single-amplifier
lsst.afw.image.Exposure
subimage that masquerades as full-detector image for a single-amp detector.- Parameters:
- parent_exposure
lsst.afw.image.Exposure
Parent image to obtain a subset from.
getDetector
must not returnNone
.- amplifier
Amplifier
Target amplifier for the subimage. May differ from the amplifier obtained by
parent_exposure.getDetector()[amplifier.getName()]
only by flips and differences ingetRawXYOffset
.
- parent_exposure
- Returns:
- subimage
lsst.afw.image.Exposure
Exposure subimage for the target amplifier, with the orientation and XY0 described by that amplifier, and a single-amp detector holding a copy of that amplifier.
- subimage
Notes
Because we use the target amplifier’s bounding box as the bounding box of the detector attached to the returned exposure, other exposure components that are passed through unmodified (e.g. the WCS) should still be valid for the single-amp exposure after it is trimmed and “assembled”. Unlike most trimmed+assembled images, however, it will have a nonzero XY0, and code that (incorrectly!) does not pay attention to XY0 may break.
- make_detector()¶
Create a single-amplifier detector that describes the transformed subimage.
- Returns:
- detector
Detector
Detector object with a single amplifier, a trimmed bounding box equal to the amplifier’s trimmed bounding box, and no crosstalk.
- detector
- transform_subimage(subimage)¶
Transform an already-extracted subimage to match the orientation and offset of the target amplifier.
- Parameters:
- subimageimage-like
The subimage to transform; may be any of
lsst.afw.image.Image
,lsst.afw.image.Mask
,lsst.afw.image.MaskedImage
, andlsst.afw.image.Exposure
.
- Returns:
- transformedimage-like
Transformed image of the same type as
subimage
.