def testShrink(self):
width, height = 5, 10 # Size of footprint
x0, y0 = 50, 50 # Position of footprint
imwidth, imheight = 100, 100 # Size of image
foot = afwDetect.Footprint(afwGeom.Box2I(afwGeom.Point2I(x0, y0), afwGeom.Extent2I(width, height)),
afwGeom.Box2I(afwGeom.Point2I(0, 0), afwGeom.Extent2I(imwidth, imheight)))
self.assertEqual(foot.getNpix(), width*height)
# Add some peaks to the original footprint and check that those lying outside
# the shrunken footprint are omitted from the returned shrunken footprint.
foot.addPeak(50, 50, 1) # should be omitted in shrunken footprint
foot.addPeak(52, 52, 2) # should be kept in shrunken footprint
foot.addPeak(50, 59, 3) # should be omitted in shrunken footprint
self.assertEqual(len(foot.getPeaks()), 3) # check that all three peaks were added
# Shrinking by one pixel makes each dimension *two* pixels shorter.
shrunk = afwDetect.shrinkFootprint(foot, 1, True)
self.assertEqual(3*8, shrunk.getNpix())
# Shrunken footprint should now only contain one peak at (52, 52)
self.assertEqual(len(shrunk.getPeaks()), 1)
peak = shrunk.getPeaks()[0]
self.assertEqual((peak.getIx(), peak.getIy()), (52, 52))
# Without shifting the centroid
self.assertEqual(shrunk.getCentroid(), foot.getCentroid())
# Get the same result from a Manhattan shrink
shrunk = afwDetect.shrinkFootprint(foot, 1, False)
self.assertEqual(3*8, shrunk.getNpix())
self.assertEqual(shrunk.getCentroid(), foot.getCentroid())
# Shrinking by a large amount leaves nothing.
self.assertEqual(afwDetect.shrinkFootprint(foot, 100, True).getNpix(), 0)
def testShrink(self):
width, height = 5, 10 # Size of footprint
x0, y0 = 50, 50 # Position of footprint
imwidth, imheight = 100, 100 # Size of image
foot = afwDetect.Footprint(afwGeom.Box2I(afwGeom.Point2I(x0, y0), afwGeom.Extent2I(width, height)),
afwGeom.Box2I(afwGeom.Point2I(0, 0), afwGeom.Extent2I(imwidth, imheight)))
self.assertEqual(foot.getNpix(), width*height)
# Add some peaks to the original footprint and check that those lying outside
# the shrunken footprint are omitted from the returned shrunken footprint.
foot.addPeak(50, 50, 1) # should be omitted in shrunken footprint
foot.addPeak(52, 52, 2) # should be kept in shrunken footprint
foot.addPeak(50, 59, 3) # should be omitted in shrunken footprint
self.assertEqual(len(foot.getPeaks()), 3) # check that all three peaks were added
# Shrinking by one pixel makes each dimension *two* pixels shorter.
shrunk = afwDetect.shrinkFootprint(foot, 1, True)
self.assertEqual(3*8, shrunk.getNpix())
# Shrunken footprint should now only contain one peak at (52, 52)
self.assertEqual(len(shrunk.getPeaks()), 1)
peak = shrunk.getPeaks()[0]
self.assertEqual((peak.getIx(), peak.getIy()), (52, 52))
# Without shifting the centroid
self.assertEqual(shrunk.getCentroid(), foot.getCentroid())
# Get the same result from a Manhattan shrink
shrunk = afwDetect.shrinkFootprint(foot, 1, False)
self.assertEqual(3*8, shrunk.getNpix())
self.assertEqual(shrunk.getCentroid(), foot.getCentroid())
# Shrinking by a large amount leaves nothing.
self.assertEqual(afwDetect.shrinkFootprint(foot, 100, True).getNpix(), 0)
def testShrinkIsoVsManhattan(self):
# Demonstrate that isotropic and Manhattan shrinks are different.
radius = 8
imwidth, imheight = 100, 100
x0, y0 = imwidth//2, imheight//2
nshrink = 4
ellipse = afwGeomEllipses.Ellipse(afwGeomEllipses.Axes(1.5*radius, 2*radius, 0),
afwGeom.Point2D(x0,y0))
foot = afwDetect.Footprint(ellipse, afwGeom.Box2I(afwGeom.Point2I(0, 0),
afwGeom.Extent2I(imwidth, imheight)))
self.assertNotEqual(afwDetect.shrinkFootprint(foot, nshrink, False),
afwDetect.shrinkFootprint(foot, nshrink, True))
def testShrinkIsoVsManhattan(self):
# Demonstrate that isotropic and Manhattan shrinks are different.
radius = 8
imwidth, imheight = 100, 100
x0, y0 = imwidth//2, imheight//2
nshrink = 4
ellipse = afwGeomEllipses.Ellipse(afwGeomEllipses.Axes(1.5*radius, 2*radius, 0),
afwGeom.Point2D(x0,y0))
foot = afwDetect.Footprint(ellipse, afwGeom.Box2I(afwGeom.Point2I(0, 0),
afwGeom.Extent2I(imwidth, imheight)))
self.assertNotEqual(afwDetect.shrinkFootprint(foot, nshrink, False),
afwDetect.shrinkFootprint(foot, nshrink, True))
def _fig8Test(self, x1, y1, x2, y2):
# Construct a "figure of 8" consisting of two circles touching at the
# centre of an image, then demonstrate that it shrinks correctly.
# (Helper method for tests below.)
radius = 3
imwidth, imheight = 100, 100
nshrink = 1
# These are the correct values for footprint sizes given the paramters
# above.
circle_npix = 29
initial_npix = circle_npix * 2 - 1 # touch at one pixel
shrunk_npix = 26
box = afwGeom.Box2I(afwGeom.Point2I(0, 0),
afwGeom.Extent2I(imwidth, imheight))
e1 = afwGeomEllipses.Ellipse(afwGeomEllipses.Axes(radius, radius, 0),
afwGeom.Point2D(x1, y1))
f1 = afwDetect.Footprint(e1, box)
self.assertEqual(f1.getNpix(), circle_npix)
e2 = afwGeomEllipses.Ellipse(afwGeomEllipses.Axes(radius, radius, 0),
afwGeom.Point2D(x2, y2))
f2 = afwDetect.Footprint(e2, box)
self.assertEqual(f2.getNpix(), circle_npix)
initial = afwDetect.mergeFootprints(f1, f2)
initial.setRegion(
f2.getRegion()) # merge does not propagate the region
self.assertEqual(initial_npix, initial.getNpix())
shrunk = afwDetect.shrinkFootprint(initial, nshrink, True)
self.assertEqual(shrunk_npix, shrunk.getNpix())
if display:
idImage = afwImage.ImageU(imwidth, imheight)
for i, foot in enumerate([initial, shrunk]):
print(foot.getNpix())
foot.insertIntoImage(idImage, i + 1)
ds9.mtv(idImage)
def _fig8Test(self, x1, y1, x2, y2):
# Construct a "figure of 8" consisting of two circles touching at the
# centre of an image, then demonstrate that it shrinks correctly.
# (Helper method for tests below.)
radius = 3
imwidth, imheight = 100, 100
nshrink = 1
# These are the correct values for footprint sizes given the paramters
# above.
circle_npix = 29
initial_npix = circle_npix * 2 - 1 # touch at one pixel
shrunk_npix = 26
box = afwGeom.Box2I(afwGeom.Point2I(0, 0), afwGeom.Extent2I(imwidth, imheight))
e1 = afwGeomEllipses.Ellipse(afwGeomEllipses.Axes(radius, radius, 0),
afwGeom.Point2D(x1, y1))
f1 = afwDetect.Footprint(e1,box)
self.assertEqual(f1.getNpix(), circle_npix)
e2 = afwGeomEllipses.Ellipse(afwGeomEllipses.Axes(radius, radius, 0),
afwGeom.Point2D(x2, y2))
f2 = afwDetect.Footprint(e2,box)
self.assertEqual(f2.getNpix(), circle_npix)
initial = afwDetect.mergeFootprints(f1, f2)
initial.setRegion(f2.getRegion()) # merge does not propagate the region
self.assertEqual(initial_npix, initial.getNpix())
shrunk = afwDetect.shrinkFootprint(initial, nshrink, True)
self.assertEqual(shrunk_npix, shrunk.getNpix())
if display:
idImage = afwImage.ImageU(imwidth, imheight)
for i, foot in enumerate([initial, shrunk]):
print foot.getNpix()
foot.insertIntoImage(idImage, i+1);
ds9.mtv(idImage)
