Coverage for tests / test_subtractBackground.py: 21%

1# This file is part of meas_algorithms. 

2# 

3# Developed for the LSST Data Management System. 

4# This product includes software developed by the LSST Project 

5# (http://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 software is dual licensed under the GNU General Public License and also 

10# under a 3-clause BSD license. Recipients may choose which of these licenses 

11# to use; please see the files gpl-3.0.txt and/or bsd_license.txt, 

12# respectively. If you choose the GPL option then the following text applies 

13# (but note that there is still no warranty even if you opt for BSD instead): 

14# 

15# This program is free software: you can redistribute it and/or modify 

16# it under the terms of the GNU General Public License as published by 

17# the Free Software Foundation, either version 3 of the License, or 

18# (at your option) any later version. 

19# 

20# This program is distributed in the hope that it will be useful, 

21# but WITHOUT ANY WARRANTY; without even the implied warranty of 

22# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 

23# GNU General Public License for more details. 

24# 

25# You should have received a copy of the GNU General Public License 

26# along with this program. If not, see <http://www.gnu.org/licenses/>. 

27import unittest 

28import numpy as np 

29 

30import lsst.geom 

31from lsst.meas.algorithms.testUtils import plantSources 

32import lsst.utils.tests 

33 

34from lsst.meas.algorithms.subtractBackground import ( 

35 SubtractBackgroundConfig, 

36 SubtractBackgroundTask, 

37 backgroundFlatContext, 

38) 

39 

40 

41class SubtractBackgroundTaskTestCase(lsst.utils.tests.TestCase): 

42 

43 def _create_exposure(self, keepSky=True): 

44 """Return a simulated exposure with some background.""" 

45 

46 bbox = lsst.geom.Box2I(lsst.geom.Point2I(0, 0), lsst.geom.Extent2I(1024, 1024)) 

47 kwid = 11 

48 self.sky = 2000 

49 

50 coordList = [[10, 10, 0, 2.0]] 

51 

52 exposure = plantSources( 

53 bbox=bbox, 

54 kwid=kwid, 

55 sky=self.sky, 

56 coordList=coordList, 

57 addPoissonNoise=True, 

58 ) 

59 if keepSky: 

60 # Add sky level back in. 

61 exposure.image.array += self.sky 

62 

63 return exposure 

64 

65 def test_subtractBackground(self): 

66 exp = self._create_exposure() 

67 

68 config = SubtractBackgroundConfig() 

69 task = SubtractBackgroundTask(config=config) 

70 

71 results = task.run(exp) 

72 

73 # Check the background was subtracted. 

74 self.assertFloatsAlmostEqual(np.mean(exp.image.array), 0.0, atol=0.1) 

75 

76 # Check the background level. 

77 backgroundImage = results.background.getImage() 

78 self.assertFloatsAlmostEqual(np.mean(backgroundImage.array), self.sky, atol=0.1) 

79 

80 # Do a second pass and confirm everything works. 

81 results2 = task.run(exp, background=results.background) 

82 self.assertEqual(len(results2.background), 2) 

83 

84 self.assertFloatsAlmostEqual(np.mean(exp.image.array), 0.0, atol=0.1) 

85 backgroundImage2 = results2.background.getImage() 

86 self.assertFloatsAlmostEqual(np.mean(backgroundImage2.array), self.sky, atol=0.1) 

87 

88 def test_subtractBackgroundWithFlatRatio(self): 

89 exp = self._create_exposure() 

90 

91 config = SubtractBackgroundConfig() 

92 config.doApplyFlatBackgroundRatio = True 

93 task = SubtractBackgroundTask(config=config) 

94 

95 ratioImage = exp.image.clone() 

96 ratioImage.array[:, :] = 2.0 

97 

98 results = task.run(exp, backgroundToPhotometricRatio=ratioImage) 

99 

100 # Check the background was subtracted. 

101 self.assertFloatsAlmostEqual(np.mean(exp.image.array), 0.0, atol=0.1) 

102 

103 # Check the background level. 

104 # This will be twice as large (in "background units") because of the 

105 # ratio scaling. 

106 backgroundImage = results.background.getImage() 

107 self.assertFloatsAlmostEqual(np.mean(backgroundImage.array), self.sky * 2.0, atol=0.2) 

108 

109 # Check that we get Raises with improper inputs. 

110 with self.assertRaises(RuntimeError): 

111 _ = task.run(exp) 

112 

113 with self.assertRaises(ValueError): 

114 _ = task.run(exp, backgroundToPhotometricRatio=exp.maskedImage) 

115 

116 def test_backgroundFlatContext(self): 

117 exp = self._create_exposure(keepSky=False) 

118 

119 # Check that doApply=False does nothing inside and out. 

120 maskedImage = exp.maskedImage.clone() 

121 with backgroundFlatContext(maskedImage, False): 

122 self.assertMaskedImagesAlmostEqual(maskedImage, exp.maskedImage) 

123 self.assertMaskedImagesAlmostEqual(maskedImage, exp.maskedImage) 

124 

125 # Check that doApply=True does the conversions correctly. 

126 ratioImage = exp.image.clone() 

127 ratioImage.array[:, :] = 2.0 

128 maskedImage = exp.maskedImage.clone() 

129 with backgroundFlatContext(maskedImage, True, backgroundToPhotometricRatio=ratioImage): 

130 comparisonImage = exp.maskedImage.clone() 

131 comparisonImage *= ratioImage 

132 self.assertMaskedImagesAlmostEqual(maskedImage, comparisonImage) 

133 self.assertMaskedImagesAlmostEqual(maskedImage, exp.maskedImage) 

134 

135 # Check that doApply=True with an incorrect ratio image raises. 

136 with self.assertRaises(ValueError): 

137 with backgroundFlatContext(maskedImage, True, backgroundToPhotometricRatio=exp.maskedImage): 

138 pass 

139 

140 # Check that doApply=True with no ratio image raises. 

141 with self.assertRaises(RuntimeError): 

142 with backgroundFlatContext(maskedImage, True): 

143 pass 

144 

145 

146class TestMemory(lsst.utils.tests.MemoryTestCase): 

147 pass 

148 

149 

150def setup_module(module): 

151 lsst.utils.tests.init() 

152 

153 

154if __name__ == "__main__": 154 ↛ 155line 154 didn't jump to line 155 because the condition on line 154 was never true

155 lsst.utils.tests.init() 

156 unittest.main()