mirror of
https://github.com/wassname/scikit-image.git
synced 2026-06-29 06:33:19 +08:00
Fixed ellipse symmetry and added some tests.
This commit is contained in:
Alexey Umnov
+27
-13
@@ -7,6 +7,15 @@ def _coords_inside_image(rr, cc, shape):
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return rr[mask], cc[mask]
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def _ellipse_in_shape(shape, center, radiuses):
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"""Generate coordinates of points within ellipse bounded by shape."""
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y, x = np.ogrid[0:shape[0], 0:shape[1]]
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cy, cx = center
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ry, rx = radiuses
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distances = ((y - cy) / ry) ** 2 + ((x - cx) / rx) ** 2
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return np.nonzero(distances < 1)
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def ellipse(cy, cx, yradius, xradius, shape=None):
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"""Generate coordinates of pixels within ellipse.
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@@ -48,21 +57,26 @@ def ellipse(cy, cx, yradius, xradius, shape=None):
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"""
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dr = 1 / float(yradius)
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dc = 1 / float(xradius)
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r, c = np.ogrid[-1:1:dr, -1:1:dc]
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rr, cc = np.nonzero(r ** 2 + c ** 2 < 1)
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rr.flags.writeable = True
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cc.flags.writeable = True
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rr += cy - yradius
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cc += cx - xradius
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center = np.array([cy, cx])
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radiuses = np.array([yradius, xradius])
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if shape is not None:
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return _coords_inside_image(rr, cc, shape)
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return _ellipse_in_shape(shape, center, radiuses)
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else:
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# rounding here is necessary to avoid rounding issues later
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upper_left = np.floor(center - radiuses)
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return rr, cc
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shifted_center = center - upper_left
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# Shifted center is in interval [radiuses, radiuses + 1], so
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# the ellipse must fit in [0, 2*radiuses + 1].
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bounding_shape = np.ceil(2 * radiuses + 1)
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rr, cc = _ellipse_in_shape(bounding_shape, shifted_center, radiuses)
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rr.flags.writeable = True
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cc.flags.writeable = True
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rr += upper_left[0]
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cc += upper_left[1]
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return rr, cc
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def circle(cy, cx, radius, shape=None):
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+139
-21
@@ -298,30 +298,134 @@ def test_circle_perimeter_aa():
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assert_array_equal(img, img_)
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def test_ellipse():
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img = np.zeros((15, 15), 'uint8')
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def test_ellipse_trivial():
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img = np.zeros((2, 2), 'uint8')
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rr, cc = ellipse(0.5, 0.5, 0.5, 0.5)
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img[rr, cc] = 1
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img_correct = np.array([
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[0, 0],
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[0, 0]
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])
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assert_array_equal(img, img_correct)
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img = np.zeros((2, 2), 'uint8')
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rr, cc = ellipse(0.5, 0.5, 1.1, 1.1)
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img[rr, cc] = 1
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img_correct = np.array([
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[1, 1],
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[1, 1],
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])
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assert_array_equal(img, img_correct)
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img = np.zeros((3, 3), 'uint8')
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rr, cc = ellipse(1, 1, 0.9, 0.9)
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img[rr, cc] = 1
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img_correct = np.array([
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[0, 0, 0],
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[0, 1, 0],
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[0, 0, 0],
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])
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assert_array_equal(img, img_correct)
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img = np.zeros((3, 3), 'uint8')
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rr, cc = ellipse(1, 1, 1.1, 1.1)
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img[rr, cc] = 1
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img_correct = np.array([
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[0, 1, 0],
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[1, 1, 1],
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[0, 1, 0],
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])
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assert_array_equal(img, img_correct)
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img = np.zeros((3, 3), 'uint8')
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rr, cc = ellipse(1, 1, 1.5, 1.5)
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img[rr, cc] = 1
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img_correct = np.array([
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[1, 1, 1],
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[1, 1, 1],
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[1, 1, 1],
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])
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assert_array_equal(img, img_correct)
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def test_ellipse_generic():
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img = np.zeros((4, 4), 'uint8')
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rr, cc = ellipse(1.5, 1.5, 1.1, 1.7)
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img[rr, cc] = 1
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img_ = np.array([
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[0, 0, 0, 0],
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[1, 1, 1, 1],
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[1, 1, 1, 1],
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[0, 0, 0, 0],
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])
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assert_array_equal(img, img_)
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img = np.zeros((5, 5), 'uint8')
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rr, cc = ellipse(2, 2, 1.7, 1.7)
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img[rr, cc] = 1
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img_ = np.array([
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[0, 0, 0, 0, 0],
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[0, 1, 1, 1, 0],
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[0, 1, 1, 1, 0],
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[0, 1, 1, 1, 0],
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[0, 0, 0, 0, 0],
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])
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assert_array_equal(img, img_)
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img = np.zeros((10, 10), 'uint8')
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rr, cc = ellipse(5, 5, 3, 4)
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img[rr, cc] = 1
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img_ = np.array([
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[0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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[0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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[0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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[0, 0, 0, 1, 1, 1, 1, 1, 0, 0],
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[0, 0, 1, 1, 1, 1, 1, 1, 1, 0],
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[0, 0, 1, 1, 1, 1, 1, 1, 1, 0],
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[0, 0, 1, 1, 1, 1, 1, 1, 1, 0],
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[0, 0, 0, 1, 1, 1, 1, 1, 0, 0],
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[0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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[0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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])
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assert_array_equal(img, img_)
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img = np.zeros((10, 10), 'uint8')
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rr, cc = ellipse(4.5, 5, 3.5, 4)
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img[rr, cc] = 1
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img_ = np.array([
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[0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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[0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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[0, 0, 0, 1, 1, 1, 1, 1, 0, 0],
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[0, 0, 1, 1, 1, 1, 1, 1, 1, 0],
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[0, 0, 1, 1, 1, 1, 1, 1, 1, 0],
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[0, 0, 1, 1, 1, 1, 1, 1, 1, 0],
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[0, 0, 1, 1, 1, 1, 1, 1, 1, 0],
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[0, 0, 0, 1, 1, 1, 1, 1, 0, 0],
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[0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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[0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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])
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assert_array_equal(img, img_)
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img = np.zeros((15, 15), 'uint8')
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rr, cc = ellipse(7, 7, 3, 7)
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img[rr, cc] = 1
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img_ = np.array(
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[[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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[0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0],
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[0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0],
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[0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0],
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[0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0],
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[0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0],
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[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]]
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)
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img_ = np.array([
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[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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[0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0],
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[0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0],
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[0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0],
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[0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0],
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[0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0],
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[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
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])
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assert_array_equal(img, img_)
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@@ -352,6 +456,20 @@ def test_ellipse_with_shape():
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assert_array_equal(img, img_)
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def test_ellipse_negative():
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rr, cc = ellipse(-3, -3, 1.7, 1.7)
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rr_, cc_ = np.nonzero(np.array([
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[0, 0, 0, 0, 0],
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[0, 1, 1, 1, 0],
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[0, 1, 1, 1, 0],
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[0, 1, 1, 1, 0],
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[0, 0, 0, 0, 0],
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]))
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assert_array_equal(rr, rr_ - 5)
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assert_array_equal(cc, cc_ - 5)
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def test_ellipse_perimeter_dot_zeroangle():
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# dot, angle == 0
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img = np.zeros((30, 15), 'uint8')
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