def testBackgroundTestImages(self):
imginfolist = []
#imginfolist.append( ["v1_i1_g_m400_s20_f.fits", 400.05551471441612] ) # cooked to known value
#imginfolist.append( ["v1_i1_g_m400_s20_f.fits", 400.00295902395123] ) # cooked to known value
#imginfolist.append( ["v1_i1_g_m400_s20_f.fits", 400.08468385712251] ) # cooked to known value
#imginfolist.append( ["v1_i1_g_m400_s20_f.fits", 400.00305806663295] ) # cooked to known value
#imginfolist.append( ["v1_i1_g_m400_s20_f.fits", 400.0035102188698] ) # cooked to known value
imginfolist.append( ["v1_i1_g_m400_s20_f.fits", 399.9912966583894] ) # cooked to known value
#imgfiles.append("v1_i1_g_m400_s20_u16.fits")
#imgfiles.append("v1_i2_g_m400_s20_f.fits"
#imgfiles.append("v1_i2_g_m400_s20_u16.fits")
#imgfiles.append("v2_i1_p_m9_f.fits")
#imgfiles.append("v2_i1_p_m9_u16.fits")
#imgfiles.append("v2_i2_p_m9_f.fits")
#imgfiles.append("v2_i2_p_m9_u16.fits")
for imginfo in imginfolist:
imgfile, centerValue = imginfo
imgPath = os.path.join(AfwdataDir, "Statistics", imgfile)
# get the image and header
dimg = afwImage.DecoratedImageF(imgPath)
img = dimg.getImage()
fitsHdr = dimg.getMetadata() # the FITS header
# get the True values of the mean and stdev
reqMean = fitsHdr.getAsDouble("MEANREQ")
reqStdev = fitsHdr.getAsDouble("SIGREQ")
naxis1 = img.getWidth()
naxis2 = img.getHeight()
# create a background control object
bctrl = afwMath.BackgroundControl(afwMath.Interpolate.AKIMA_SPLINE)
bctrl.setNxSample(5)
bctrl.setNySample(5)
# run the background constructor and call the getPixel() and getImage() functions.
backobj = afwMath.makeBackground(img, bctrl)
pixPerSubimage = img.getWidth()*img.getHeight()/(bctrl.getNxSample()*bctrl.getNySample())
stdevInterp = reqStdev/math.sqrt(pixPerSubimage)
# test getPixel()
testval = afwMath.cast_BackgroundMI(backobj).getPixel(naxis1//2, naxis2//2)
self.assertAlmostEqual(testval/centerValue, 1, places=7)
self.assertTrue( abs(testval - reqMean) < 2*stdevInterp )
# test getImage() by checking the center pixel
bimg = backobj.getImageF()
testImgval = bimg.get(naxis1//2, naxis2//2)
self.assertTrue( abs(testImgval - reqMean) < 2*stdevInterp )
def testSampleImageStats(self):
""" Compare our results to known values in test data """
imgfiles = []
imgfiles.append("v1_i1_g_m400_s20_f.fits")
imgfiles.append("v1_i1_g_m400_s20_u16.fits")
imgfiles.append("v1_i2_g_m400_s20_f.fits")
imgfiles.append("v1_i2_g_m400_s20_u16.fits")
imgfiles.append("v2_i1_p_m9_f.fits")
imgfiles.append("v2_i1_p_m9_u16.fits")
imgfiles.append("v2_i2_p_m9_f.fits")
imgfiles.append("v2_i2_p_m9_u16.fits")
afwdataDir = os.getenv("AFWDATA_DIR")
if not afwdataDir:
print >> sys.stderr, "Skipping tests as afwdata is not setup"
return
for imgfile in imgfiles:
imgPath = os.path.join(afwdataDir, "Statistics", imgfile)
# get the image and header
dimg = afwImage.DecoratedImageF(imgPath)
fitsHdr = dimg.getMetadata()
# get the true values of the mean and stdev
trueMean = fitsHdr.getAsDouble("MEANCOMP")
trueStdev = fitsHdr.getAsDouble("SIGCOMP")
# measure the mean and stdev with the Statistics class
img = dimg.getImage()
statobj = afwMath.makeStatistics(img, afwMath.MEAN | afwMath.STDEV)
mean = statobj.getValue(afwMath.MEAN)
stdev = statobj.getValue(afwMath.STDEV)
# print trueMean, mean, trueStdev, stdev
self.assertAlmostEqual(mean, trueMean, 8)
self.assertAlmostEqual(stdev, trueStdev, 8)