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fix region merging

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correct variable names

add test for felzenszwalb's region merging
This commit is contained in:
mljli
2016-06-21 12:17:29 +00:00
parent 2cef2a9b25
commit 7ee54affab
2 changed files with 19 additions and 6 deletions
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skimage/segmentation/_felzenszwalb_cy.pyx
+6 -4
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@@ -52,9 +52,9 @@ def _felzenszwalb_cython(image, double scale=1, sigma=0.8,
image = ndi.gaussian_filter(image, sigma=[sigma, sigma, 0])
# compute edge weights in 8 connectivity:
right_cost = np.sqrt(np.sum((image[1:, :, :] - image[:-1, :, :])
down_cost = np.sqrt(np.sum((image[1:, :, :] - image[:-1, :, :])
*(image[1:, :, :] - image[:-1, :, :]), axis=-1))
down_cost = np.sqrt(np.sum((image[:, 1:, :] - image[:, :-1, :])
right_cost = np.sqrt(np.sum((image[:, 1:, :] - image[:, :-1, :])
*(image[:, 1:, :] - image[:, :-1, :]), axis=-1))
dright_cost = np.sqrt(np.sum((image[1:, 1:, :] - image[:-1, :-1, :])
*(image[1:, 1:, :] - image[:-1, :-1, :]), axis=-1))
@@ -68,8 +68,8 @@ def _felzenszwalb_cython(image, double scale=1, sigma=0.8,
height, width = image.shape[:2]
cdef cnp.ndarray[cnp.intp_t, ndim=2] segments \
= np.arange(width * height, dtype=np.intp).reshape(height, width)
right_edges = np.c_[segments[1:, :].ravel(), segments[:-1, :].ravel()]
down_edges = np.c_[segments[:, 1:].ravel(), segments[:, :-1].ravel()]
down_edges = np.c_[segments[1:, :].ravel(), segments[:-1, :].ravel()]
right_edges = np.c_[segments[:, 1:].ravel(), segments[:, :-1].ravel()]
dright_edges = np.c_[segments[1:, 1:].ravel(), segments[:-1, :-1].ravel()]
uright_edges = np.c_[segments[:-1, 1:].ravel(), segments[1:, :-1].ravel()]
cdef cnp.ndarray[cnp.intp_t, ndim=2] edges \
@@ -122,6 +122,8 @@ def _felzenszwalb_cython(image, double scale=1, sigma=0.8,
continue
if segment_size[seg0] < min_size or segment_size[seg1] < min_size:
join_trees(segments_p, seg0, seg1)
seg_new = find_root(segments_p, seg0)
segment_size[seg_new] = segment_size[seg0] + segment_size[seg1]
# unravel the union find tree
flat = segments.ravel()
skimage/segmentation/tests/test_felzenszwalb.py
+13 -2
View File
@@ -7,7 +7,7 @@ from skimage import data
@test_parallel()
def test_grey():
# very weak tests. This algorithm is pretty unstable.
# very weak tests.
img = np.zeros((20, 21))
img[:10, 10:] = 0.2
img[10:, :10] = 0.4
@@ -38,7 +38,7 @@ def test_minsize():
def test_color():
# very weak tests. This algorithm is pretty unstable.
# very weak tests.
img = np.zeros((20, 21, 3))
img[:10, :10, 0] = 1
img[10:, :10, 1] = 1
@@ -52,6 +52,17 @@ def test_color():
assert_array_equal(seg[10:, 10:], 3)
def test_merging():
# test region merging in the post-processing step
img = np.array([[0, 0.3], [0.7, 1]])
# With scale=0, only the post-processing is performed.
seg = felzenszwalb(img, scale=0, sigma=0, min_size=2)
# we expect 2 segments:
assert_equal(len(np.unique(seg)), 2)
assert_array_equal(seg[0, :], 0)
assert_array_equal(seg[1, :], 1)
if __name__ == '__main__':
from numpy import testing
testing.run_module_suite()