lsst.ip.isr  16.0-22-g62d8060+2
vignette.py
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1 # This file is part of ip_isr.
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 #
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21 import numpy
22 
23 import lsst.afw.geom as afwGeom
24 
25 from lsst.pex.config import Config, Field
26 from lsst.pipe.base import Task
27 
28 
29 class VignetteConfig(Config):
30  """
31  Settings to define vignetteing pattern
32  """
33  xCenter = Field(
34  dtype=float,
35  doc="Center of vignetting pattern, in focal plane x coordinates.",
36  default=0.0,
37  )
38  yCenter = Field(
39  dtype=float,
40  doc="Center of vignetting pattern, in focal plane y coordinates.",
41  default=0.0,
42  )
43  radius = Field(
44  dtype=float,
45  doc="Radius of vignetting pattern, in focal plane coordinates.",
46  default=100.0,
47  check=lambda x: x >= 0
48  )
49  numPolygonPoints = Field(
50  dtype=int,
51  doc="Number of points used to define the vignette polygon.",
52  default=100,
53  )
54  doWriteVignettePolygon = Field(
55  dtype=bool,
56  doc="Persist polygon used to define vignetted region?",
57  default=False,
58  )
59 
60 
61 class VignetteTask(Task):
62  """Define a simple circular vignette pattern.
63  """
64  ConfigClass = VignetteConfig
65  _DefaultName = "isrVignette"
66 
67  def run(self, exposure):
68  """Generate circular vignette pattern.
69 
70  Parameters
71  ----------
72  exposure : `lsst.afw.image.Exposure`
73  Exposure to construct vignette for.
74 
75  Returns
76  -------
77  polygon : `lsst.afw.Geom.Polygon`
78  Polygon defining the boundary of the vignetted region.
79  """
80 
81  if self.config.doWriteVignettePolygon:
82  theta = numpy.linspace(0, 2*numpy.pi, num=self.config.numPolygonPoints, endpoint=False)
83  x = self.config.radius*numpy.cos(theta) + self.config.xCenter
84  y = self.config.radius*numpy.sin(theta) + self.config.yCenter
85  points = numpy.array([x, y]).transpose()
86  polygon = afwGeom.Polygon([afwGeom.Point2D(x1, y1) for x1, y1 in reversed(points)])
87  return polygon
88  else:
89  return None