Coverage for python/lsst/obs/base/_fitsRawFormatterBase.py : 26%

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1# This file is part of obs_base.
2#
3# Developed for the LSST Data Management System.
4# This product includes software developed by the LSST Project
5# (https://www.lsst.org).
6# See the COPYRIGHT file at the top-level directory of this distribution
7# for details of code ownership.
8#
9# This program is free software: you can redistribute it and/or modify
10# it under the terms of the GNU General Public License as published by
11# the Free Software Foundation, either version 3 of the License, or
12# (at your option) any later version.
13#
14# This program is distributed in the hope that it will be useful,
15# but WITHOUT ANY WARRANTY; without even the implied warranty of
16# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17# GNU General Public License for more details.
18#
19# You should have received a copy of the GNU General Public License
20# along with this program. If not, see <http://www.gnu.org/licenses/>.
22__all__ = ("FitsRawFormatterBase",)
24from abc import ABCMeta, abstractmethod
26from astro_metadata_translator import ObservationInfo
28import lsst.afw.fits
29import lsst.afw.geom
30import lsst.afw.image
31from lsst.daf.butler import FileDescriptor
32import lsst.log
34from .formatters.fitsExposure import FitsExposureFormatter
35from .makeRawVisitInfoViaObsInfo import MakeRawVisitInfoViaObsInfo
36from .utils import createInitialSkyWcsFromBoresight, InitialSkyWcsError
39class FitsRawFormatterBase(FitsExposureFormatter, metaclass=ABCMeta):
40 """Abstract base class for reading and writing raw data to and from
41 FITS files.
42 """
44 def __init__(self, *args, **kwargs):
45 self.filterDefinitions.reset()
46 self.filterDefinitions.defineFilters()
47 super().__init__(*args, **kwargs)
49 @classmethod
50 def fromMetadata(cls, metadata, obsInfo=None, storageClass=None, location=None):
51 """Construct a possibly-limited formatter from known metadata.
53 Parameters
54 ----------
55 metadata : `lsst.daf.base.PropertyList`
56 Raw header metadata, with any fixes (see
57 `astro_metadata_translator.fix_header`) applied but nothing
58 stripped.
59 obsInfo : `astro_metadata_translator.ObservationInfo`, optional
60 Structured information already extracted from ``metadata``.
61 If not provided, will be read from ``metadata`` on first use.
62 storageClass : `lsst.daf.butler.StorageClass`, optional
63 StorageClass for this file. If not provided, the formatter will
64 only support `makeWcs`, `makeVisitInfo`, `makeFilter`, and other
65 operations that operate purely on metadata and not the actual file.
66 location : `lsst.daf.butler.Location`, optional.
67 Location of the file. If not provided, the formatter will only
68 support `makeWcs`, `makeVisitInfo`, `makeFilter`, and other
69 operations that operate purely on metadata and not the actual file.
71 Returns
72 -------
73 formatter : `FitsRawFormatterBase`
74 An instance of ``cls``.
75 """
76 self = cls(FileDescriptor(location, storageClass))
77 self._metadata = metadata
78 self._observationInfo = obsInfo
79 return self
81 @property
82 @abstractmethod
83 def translatorClass(self):
84 """`~astro_metadata_translator.MetadataTranslator` to translate
85 metadata header to `~astro_metadata_translator.ObservationInfo`.
86 """
87 return None
89 _observationInfo = None
91 @property
92 @abstractmethod
93 def filterDefinitions(self):
94 """`~lsst.obs.base.FilterDefinitions`, defining the filters for this
95 instrument.
96 """
97 return None
99 def readImage(self):
100 """Read just the image component of the Exposure.
102 Returns
103 -------
104 image : `~lsst.afw.image.Image`
105 In-memory image component.
106 """
107 return lsst.afw.image.ImageU(self.fileDescriptor.location.path)
109 def readMask(self):
110 """Read just the mask component of the Exposure.
112 May return None (as the default implementation does) to indicate that
113 there is no mask information to be extracted (at least not trivially)
114 from the raw data. This will prohibit direct reading of just the mask,
115 and set the mask of the full Exposure to zeros.
117 Returns
118 -------
119 mask : `~lsst.afw.image.Mask`
120 In-memory mask component.
121 """
122 return None
124 def readVariance(self):
125 """Read just the variance component of the Exposure.
127 May return None (as the default implementation does) to indicate that
128 there is no variance information to be extracted (at least not
129 trivially) from the raw data. This will prohibit direct reading of
130 just the variance, and set the variance of the full Exposure to zeros.
132 Returns
133 -------
134 image : `~lsst.afw.image.Image`
135 In-memory variance component.
136 """
137 return None
139 def isOnSky(self):
140 """Boolean to determine if the exposure is thought to be on the sky.
142 Returns
143 -------
144 onSky : `bool`
145 Returns `True` if the observation looks like it was taken on the
146 sky. Returns `False` if this observation looks like a calibration
147 observation.
149 Notes
150 -----
151 If there is tracking RA/Dec information associated with the
152 observation it is assumed that the observation is on sky.
153 Currently the observation type is not checked.
154 """
155 if self.observationInfo.tracking_radec is None:
156 return False
157 return True
159 def stripMetadata(self):
160 """Remove metadata entries that are parsed into components.
161 """
162 # NOTE: makeVisitInfo() may not strip any metadata itself, but calling
163 # it ensures that ObservationInfo is created from the metadata, which
164 # will strip the VisitInfo keys and more.
165 self.makeVisitInfo()
166 self._createSkyWcsFromMetadata()
168 def makeVisitInfo(self):
169 """Construct a VisitInfo from metadata.
171 Returns
172 -------
173 visitInfo : `~lsst.afw.image.VisitInfo`
174 Structured metadata about the observation.
175 """
176 return MakeRawVisitInfoViaObsInfo.observationInfo2visitInfo(self.observationInfo)
178 @abstractmethod
179 def getDetector(self, id):
180 """Return the detector that acquired this raw exposure.
182 Parameters
183 ----------
184 id : `int`
185 The identifying number of the detector to get.
187 Returns
188 -------
189 detector : `~lsst.afw.cameraGeom.Detector`
190 The detector associated with that ``id``.
191 """
192 raise NotImplementedError("Must be implemented by subclasses.")
194 def makeWcs(self, visitInfo, detector):
195 """Create a SkyWcs from information about the exposure.
197 If VisitInfo is not None, use it and the detector to create a SkyWcs,
198 otherwise return the metadata-based SkyWcs (always created, so that
199 the relevant metadata keywords are stripped).
201 Parameters
202 ----------
203 visitInfo : `~lsst.afw.image.VisitInfo`
204 The information about the telescope boresight and camera
205 orientation angle for this exposure.
206 detector : `~lsst.afw.cameraGeom.Detector`
207 The detector used to acquire this exposure.
209 Returns
210 -------
211 skyWcs : `~lsst.afw.geom.SkyWcs`
212 Reversible mapping from pixel coordinates to sky coordinates.
214 Raises
215 ------
216 InitialSkyWcsError
217 Raised if there is an error generating the SkyWcs, chained from the
218 lower-level exception if available.
219 """
220 if not self.isOnSky():
221 # This is not an on-sky observation
222 return None
224 skyWcs = self._createSkyWcsFromMetadata()
226 log = lsst.log.Log.getLogger("fitsRawFormatter")
227 if visitInfo is None:
228 msg = "No VisitInfo; cannot access boresight information. Defaulting to metadata-based SkyWcs."
229 log.warn(msg)
230 if skyWcs is None:
231 raise InitialSkyWcsError("Failed to create both metadata and boresight-based SkyWcs."
232 "See warnings in log messages for details.")
233 return skyWcs
235 return self.makeRawSkyWcsFromBoresight(visitInfo.getBoresightRaDec(),
236 visitInfo.getBoresightRotAngle(),
237 detector)
239 @classmethod
240 def makeRawSkyWcsFromBoresight(cls, boresight, orientation, detector):
241 """Class method to make a raw sky WCS from boresight and detector.
243 Parameters
244 ----------
245 boresight : `lsst.geom.SpherePoint`
246 The ICRS boresight RA/Dec
247 orientation : `lsst.geom.Angle`
248 The rotation angle of the focal plane on the sky.
249 detector : `lsst.afw.cameraGeom.Detector`
250 Where to get the camera geomtry from.
252 Returns
253 -------
254 skyWcs : `~lsst.afw.geom.SkyWcs`
255 Reversible mapping from pixel coordinates to sky coordinates.
256 """
257 return createInitialSkyWcsFromBoresight(boresight, orientation, detector)
259 def _createSkyWcsFromMetadata(self):
260 """Create a SkyWcs from the FITS header metadata in an Exposure.
262 Returns
263 -------
264 skyWcs: `lsst.afw.geom.SkyWcs`, or None
265 The WCS that was created from ``self.metadata``, or None if that
266 creation fails due to invalid metadata.
267 """
268 if not self.isOnSky():
269 # This is not an on-sky observation
270 return None
272 try:
273 return lsst.afw.geom.makeSkyWcs(self.metadata, strip=True)
274 except TypeError as e:
275 log = lsst.log.Log.getLogger("fitsRawFormatter")
276 log.warn("Cannot create a valid WCS from metadata: %s", e.args[0])
277 return None
279 def makeFilter(self):
280 """Construct a Filter from metadata.
282 Returns
283 -------
284 filter : `~lsst.afw.image.Filter`
285 Object that identifies the filter for this image.
287 Raises
288 ------
289 NotFoundError
290 Raised if the physical filter was not registered via
291 `~lsst.afw.image.utils.defineFilter`.
292 """
293 return lsst.afw.image.Filter(self.observationInfo.physical_filter)
295 def readComponent(self, component, parameters=None):
296 """Read a component held by the Exposure.
298 Parameters
299 ----------
300 component : `str`, optional
301 Component to read from the file.
302 parameters : `dict`, optional
303 If specified, a dictionary of slicing parameters that
304 overrides those in ``fileDescriptor``.
306 Returns
307 -------
308 obj : component-dependent
309 In-memory component object.
311 Raises
312 ------
313 KeyError
314 Raised if the requested component cannot be handled.
315 """
316 if component == "image":
317 return self.readImage()
318 elif component == "mask":
319 return self.readMask()
320 elif component == "variance":
321 return self.readVariance()
322 elif component == "filter":
323 return self.makeFilter()
324 elif component == "visitInfo":
325 return self.makeVisitInfo()
326 elif component == "wcs":
327 detector = self.getDetector(self.observationInfo.detector_num)
328 visitInfo = self.makeVisitInfo()
329 return self.makeWcs(visitInfo, detector)
330 return None
332 def readFull(self, parameters=None):
333 """Read the full Exposure object.
335 Parameters
336 ----------
337 parameters : `dict`, optional
338 If specified, a dictionary of slicing parameters that overrides
339 those in the `fileDescriptor` attribute.
341 Returns
342 -------
343 exposure : `~lsst.afw.image.Exposure`
344 Complete in-memory exposure.
345 """
346 from lsst.afw.image import makeExposure, makeMaskedImage
347 full = makeExposure(makeMaskedImage(self.readImage()))
348 mask = self.readMask()
349 if mask is not None:
350 full.setMask(mask)
351 variance = self.readVariance()
352 if variance is not None:
353 full.setVariance(variance)
354 full.setDetector(self.getDetector(self.observationInfo.detector_num))
355 info = full.getInfo()
356 info.setFilter(self.makeFilter())
357 info.setVisitInfo(self.makeVisitInfo())
358 info.setWcs(self.makeWcs(info.getVisitInfo(), info.getDetector()))
359 # We don't need to call stripMetadata() here because it has already
360 # been stripped during creation of the ObservationInfo, WCS, etc.
361 full.setMetadata(self.metadata)
362 return full
364 def readRawHeaderWcs(self, parameters=None):
365 """Read the SkyWcs stored in the un-modified raw FITS WCS header keys.
366 """
367 return lsst.afw.geom.makeSkyWcs(lsst.afw.fits.readMetadata(self.fileDescriptor))
369 def write(self, inMemoryDataset):
370 """Write a Python object to a file.
372 Parameters
373 ----------
374 inMemoryDataset : `object`
375 The Python object to store.
377 Returns
378 -------
379 path : `str`
380 The `URI` where the primary file is stored.
381 """
382 raise NotImplementedError("Raw data cannot be `put`.")
384 @property
385 def observationInfo(self):
386 """The `~astro_metadata_translator.ObservationInfo` extracted from
387 this file's metadata (`~astro_metadata_translator.ObservationInfo`,
388 read-only).
389 """
390 if self._observationInfo is None:
391 self._observationInfo = ObservationInfo(self.metadata, translator_class=self.translatorClass)
392 return self._observationInfo