mirror of
https://github.com/wassname/scikit-image.git
synced 2026-06-29 05:01:42 +08:00
Josh Warner (Mac)
62 lines
2.3 KiB
Python
62 lines
2.3 KiB
Python
import numpy as np
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from numpy.testing import assert_raises
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from skimage.draw import ellipsoid, ellipsoid_stats
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from skimage.measure import (marching_cubes, mesh_surface_area,
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correct_mesh_orientation)
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def test_marching_cubes_isotropic():
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ellipsoid_isotropic = ellipsoid(6, 10, 16, levelset=True)
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_, surf = ellipsoid_stats(6, 10, 16)
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verts, faces = marching_cubes(ellipsoid_isotropic, 0.)
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surf_calc = mesh_surface_area(verts, faces)
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# Test within 1% tolerance for isotropic. Will always underestimate.
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assert surf > surf_calc and surf_calc > surf * 0.99
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def test_marching_cubes_anisotropic():
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spacing = (1., 10 / 6., 16 / 6.)
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ellipsoid_anisotropic = ellipsoid(6, 10, 16, spacing=spacing,
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levelset=True)
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_, surf = ellipsoid_stats(6, 10, 16)
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verts, faces = marching_cubes(ellipsoid_anisotropic, 0.,
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spacing=spacing)
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surf_calc = mesh_surface_area(verts, faces)
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# Test within 1.5% tolerance for anisotropic. Will always underestimate.
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assert surf > surf_calc and surf_calc > surf * 0.985
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def test_invalid_input():
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assert_raises(ValueError, marching_cubes, np.zeros((2, 2, 1)), 0)
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assert_raises(ValueError, marching_cubes, np.zeros((2, 2, 1)), 1)
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assert_raises(ValueError, marching_cubes, np.ones((3, 3, 3)), 1,
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spacing=(1, 2))
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assert_raises(ValueError, marching_cubes, np.zeros((20, 20)), 0)
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def test_correct_mesh_orientation():
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sphere_small = ellipsoid(1, 1, 1, levelset=True)
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verts, faces = marching_cubes(sphere_small, 0.)
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# Correct mesh orientation - descent
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corrected_faces1 = correct_mesh_orientation(sphere_small, verts, faces,
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gradient_direction='descent')
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corrected_faces2 = correct_mesh_orientation(sphere_small, verts, faces,
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gradient_direction='ascent')
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# Ensure ascent is opposite of descent for all faces
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np.testing.assert_array_equal(corrected_faces1, corrected_faces2[:, ::-1])
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# Ensure correct faces have been reversed: 1, 4, and 5
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idx = [1, 4, 5]
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expected = faces.copy()
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expected[idx] = expected[idx, ::-1]
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np.testing.assert_array_equal(expected, corrected_faces1)
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if __name__ == '__main__':
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np.testing.run_module_suite()
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