lsst.ip.isr  22.0.1-17-gb1dbe93+4f1b862ccf
ampOffset.py
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2 #
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5 # (https://www.lsst.org).
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21 # import os
22 
23 import lsst.pex.config as pexConfig
24 import lsst.pipe.base as pipeBase
25 from lsst.meas.algorithms import (SubtractBackgroundTask, SourceDetectionTask)
26 
27 
28 class AmpOffsetConfig(pexConfig.Config):
29  """Configuration parameters for AmpOffsetTask.
30  """
31  ampEdgeInset = pexConfig.Field(
32  doc="Number of pixels the amp edge strip is inset from the amp edge. A thin strip of pixels running "
33  "parallel to the edge of the amp is used to characterize the average flux level at the amp edge.",
34  dtype=int,
35  default=5,
36  )
37  ampEdgeWidth = pexConfig.Field(
38  doc="Pixel width of the amp edge strip, starting at ampEdgeInset and extending inwards.",
39  dtype=int,
40  default=64,
41  )
42  ampEdgeMinFrac = pexConfig.Field(
43  doc="Minimum allowed fraction of viable pixel rows along an amp edge. No amp offset estimate will be "
44  "generated for amp edges that do not have at least this fraction of unmasked pixel rows.",
45  dtype=float,
46  default=0.5,
47  )
48  ampEdgeMaxOffset = pexConfig.Field(
49  doc="Maximum allowed amp offset ADU value. If a measured amp offset value is larger than this, the "
50  "result will be discarded and therefore not used to determine amp pedestal corrections.",
51  dtype=float,
52  default=5.0,
53  )
54  ampEdgeWindow = pexConfig.Field(
55  doc="Pixel size of the sliding window used to generate rolling average amp offset values.",
56  dtype=int,
57  default=512,
58  )
59  doBackground = pexConfig.Field(
60  doc="Estimate and subtract background prior to amp offset estimation?",
61  dtype=bool,
62  default=True,
63  )
64  background = pexConfig.ConfigurableField(
65  doc="An initial background estimation step run prior to amp offset calculation.",
66  target=SubtractBackgroundTask,
67  )
68  doDetection = pexConfig.Field(
69  doc="Detect sources and update cloned exposure prior to amp offset estimation?",
70  dtype=bool,
71  default=True,
72  )
73  detection = pexConfig.ConfigurableField(
74  doc="Source detection to add temporary detection footprints prior to amp offset calculation.",
75  target=SourceDetectionTask,
76  )
77 
78 
79 class AmpOffsetTask(pipeBase.Task):
80  """Calculate and apply amp offset corrections to an exposure.
81  """
82  ConfigClass = AmpOffsetConfig
83  _DefaultName = "isrAmpOffset"
84 
85  def __init__(self, *args, **kwargs):
86  super().__init__(**kwargs)
87  # always load background subtask, even if doBackground=False;
88  # this allows for default plane bit masks to be defined
89  self.makeSubtask("background")
90  if self.config.doDetection:
91  self.makeSubtask("detection")
92 
93  def run(self, exposure):
94  """Calculate amp offset values, determine corrective pedestals for each
95  amp, and update the input exposure in-place. This task is currently not
96  implemented, and should be retargeted by a camera specific version.
97 
98  Parameters
99  ----------
100  exposure : `lsst.afw.image.Exposure`
101  Exposure to be corrected for any amp offsets.
102  """
103  raise NotImplementedError("Amp offset task should be retargeted by a camera specific version.")
def __init__(self, *args, **kwargs)
Definition: ampOffset.py:85