def readImage(filename=None):
"""Read an image and background subtract it"""
if not filename:
try:
afwDataDir = lsst.utils.getPackageDir("afwdata")
except Exception:
raise RuntimeError(
"You must provide a filename or setup afwdata to run these examples"
)
filename = os.path.join(afwDataDir, "CFHT", "D4",
"cal-53535-i-797722_1.fits")
bbox = afwGeom.Box2I(afwGeom.Point2I(270, 2530),
afwGeom.Extent2I(512, 512))
else:
bbox = None
mi = afwImage.MaskedImageF(filename, bbox=bbox, origin=afwImage.LOCAL)
mi.setXY0(afwGeom.Point2I(0, 0))
#
# Subtract the background. We'd use a canned procedure, but that's in meas/utils/sourceDetection.py. We
# can't fix those pesky cosmic rays either, as that's in a dependent product (meas/algorithms) too
#
bctrl = afwMath.BackgroundControl(afwMath.Interpolate.NATURAL_SPLINE)
bctrl.setNxSample(int(mi.getWidth() / 256) + 1)
bctrl.setNySample(int(mi.getHeight() / 256) + 1)
sctrl = bctrl.getStatisticsControl()
sctrl.setNumSigmaClip(3.0)
sctrl.setNumIter(2)
im = mi.getImage()
try:
backobj = afwMath.makeBackground(im, bctrl)
except Exception as e:
print(e, end=' ', file=sys.stderr)
bctrl.setInterpStyle(afwMath.Interpolate.CONSTANT)
backobj = afwMath.makeBackground(im, bctrl)
im -= backobj.getImageF()
#
# Find sources
#
threshold = afwDetect.Threshold(5, afwDetect.Threshold.STDEV)
npixMin = 5 # we didn't smooth
fs = afwDetect.FootprintSet(mi, threshold, "DETECTED", npixMin)
grow, isotropic = 1, False
fs = afwDetect.FootprintSet(fs, grow, isotropic)
fs.setMask(mi.getMask(), "DETECTED")
return mi, fs
def readImage(filename=None):
"""Read an image and background subtract it"""
if not filename:
try:
afwDataDir = lsst.utils.getPackageDir("afwdata")
except Exception:
raise RuntimeError(
"You must provide a filename or setup afwdata to run these examples"
)
filename = os.path.join(afwDataDir, "CFHT", "D4",
"cal-53535-i-797722_1")
bbox = afwGeom.Box2I(afwGeom.Point2I(270, 2530),
afwGeom.Extent2I(512, 512))
else:
bbox = None
mi = afwImage.MaskedImageF(filename, 0, None, bbox, afwImage.LOCAL)
mi.setXY0(afwGeom.Point2I(0, 0))
#
# Subtract the background. We'd use a canned procedure, but that's in meas/utils/sourceDetection.py. We
# can't fix those pesky cosmic rays either, as that's in a dependent product (meas/algorithms) too
#
bctrl = afwMath.BackgroundControl(afwMath.Interpolate.NATURAL_SPLINE)
bctrl.setNxSample(int(mi.getWidth() / 256) + 1)
bctrl.setNySample(int(mi.getHeight() / 256) + 1)
sctrl = bctrl.getStatisticsControl()
sctrl.setNumSigmaClip(3.0)
sctrl.setNumIter(2)
im = mi.getImage()
try:
backobj = afwMath.makeBackground(im, bctrl)
except Exception, e:
print >> sys.stderr, e,
bctrl.setInterpStyle(afwMath.Interpolate.CONSTANT)
backobj = afwMath.makeBackground(im, bctrl)
def backgroundSubtract(config, maskedImages):
backgrounds = []
t0 = time.time()
algorithm = config.algorithm
binsize = config.binSize
undersample = config.undersampleStyle
bctrl = afwMath.BackgroundControl(algorithm)
bctrl.setUndersampleStyle(undersample)
for maskedImage in maskedImages:
bctrl.setNxSample(maskedImage.getWidth() // binsize + 1)
bctrl.setNySample(maskedImage.getHeight() // binsize + 1)
image = maskedImage.getImage()
backobj = afwMath.makeBackground(image, bctrl)
image -= backobj.getImageF()
backgrounds.append(backobj.getImageF())
del backobj
t1 = time.time()
logger = Log.getLogger("ip.diffim.backgroundSubtract")
logger.debug("Total time for background subtraction : %.2f s", (t1 - t0))
return backgrounds
def backgroundSubtract(config, maskedImages):
"""Subtract the background from masked images.
Parameters
----------
config : TODO: DM-17458
TODO: DM-17458
maskedImages : `list` of `lsst.afw.image.MaskedImage`
TODO: DM-17458
Returns
-------
TODO: DM-17458
TODO: DM-17458
"""
backgrounds = []
t0 = time.time()
algorithm = config.algorithm
binsize = config.binSize
undersample = config.undersampleStyle
bctrl = afwMath.BackgroundControl(algorithm)
bctrl.setUndersampleStyle(undersample)
for maskedImage in maskedImages:
bctrl.setNxSample(maskedImage.getWidth() // binsize + 1)
bctrl.setNySample(maskedImage.getHeight() // binsize + 1)
image = maskedImage.getImage()
backobj = afwMath.makeBackground(image, bctrl)
image -= backobj.getImageF()
backgrounds.append(backobj.getImageF())
del backobj
t1 = time.time()
logger = Log.getLogger("ip.diffim.backgroundSubtract")
logger.debug("Total time for background subtraction : %.2f s", (t1 - t0))
return backgrounds
