def testGainAndReadnoise(self):
isrTask = IsrTask()
detector = DetectorWrapper().detector
raw = afwImage.ExposureF(detector.getBBox())
level = 10
readNoise = 1.5
raw.image.set(level)
amp = detector[0]
for gain in [-1, 0, 0.1, 1, np.NaN]:
# Because amplifiers are immutable, we can't change the gain or
# read noise in-place. Instead, we clone, and update the clone.
testAmp = Amplifier.Builder()
testAmp.assign(amp)
testAmp.setReadNoise(readNoise)
testAmp.setGain(gain)
testAmp.finish()
isrTask.updateVariance(raw, testAmp)
if gain <= 0: # behave the same way as amp.setGain
gain = 1
if math.isnan(gain):
gain = 1
self.assertEqual(raw.variance[0, 0, afwImage.LOCAL],
level / gain + readNoise**2)
def testGainAndReadnoise(self):
import lsst.afw.image as afwImage
from lsst.afw.cameraGeom.testUtils import DetectorWrapper
from lsst.ip.isr import IsrTask
isrTask = IsrTask()
detector = DetectorWrapper().detector
raw = afwImage.ExposureF(detector.getBBox())
level = 10
readNoise = 1
raw.image.set(level)
amp = detector[0]
amp.setReadNoise(readNoise)
for gain in [-1, 0, 0.1, 1]:
amp.setGain(gain)
isrTask.updateVariance(raw, amp)
if gain <= 0:
gain = 1
self.assertEqual(raw.variance[0, 0, afwImage.LOCAL],
level / gain + readNoise**2)
def testGainAndReadnoise(self):
import lsst.afw.image as afwImage
from lsst.afw.cameraGeom.testUtils import DetectorWrapper
from lsst.ip.isr import IsrTask
isrTask = IsrTask()
detector = DetectorWrapper().detector
raw = afwImage.ExposureF(detector.getBBox())
level = 10
readNoise = 1
raw.image.set(level)
amp = detector[0]
amp.setReadNoise(readNoise)
for gain in [-1, 0, 0.1, 1]:
amp.setGain(gain)
isrTask.updateVariance(raw, amp)
if gain <= 0:
gain = 1
self.assertEqual(raw.variance[0, 0, afwImage.LOCAL], level/gain + readNoise**2)
