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scikit-image/skimage/transform/tests/test_hough_transform.py
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Julius Bier Kirekgaard e79a0a2dc1 Added pep8 spaces
2015-08-30 15:35:50 +01:00

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Python

import numpy as np
from numpy.testing import assert_almost_equal, assert_equal
import skimage.transform as tf
from skimage.draw import line, circle_perimeter, ellipse_perimeter
from skimage._shared._warnings import expected_warnings
from skimage._shared.testing import test_parallel
def append_desc(func, description):
"""Append the test function ``func`` and append
``description`` to its name.
"""
func.description = func.__module__ + '.' + func.__name__ + description
return func
@test_parallel()
def test_hough_line():
# Generate a test image
img = np.zeros((100, 150), dtype=int)
rr, cc = line(60, 130, 80, 10)
img[rr, cc] = 1
out, angles, d = tf.hough_line(img)
y, x = np.where(out == out.max())
dist = d[y[0]]
theta = angles[x[0]]
assert_almost_equal(dist, 80.723, 1)
assert_almost_equal(theta, 1.41, 1)
def test_hough_line_angles():
img = np.zeros((10, 10))
img[0, 0] = 1
out, angles, d = tf.hough_line(img, np.linspace(0, 360, 10))
assert_equal(len(angles), 10)
def test_probabilistic_hough():
# Generate a test image
img = np.zeros((100, 100), dtype=int)
for i in range(25, 75):
img[100 - i, i] = 100
img[i, i] = 100
# decrease default theta sampling because similar orientations may confuse
# as mentioned in article of Galambos et al
theta = np.linspace(0, np.pi, 45)
lines = tf.probabilistic_hough_line(img, threshold=10, line_length=10,
line_gap=1, theta=theta)
# sort the lines according to the x-axis
sorted_lines = []
for line in lines:
line = list(line)
line.sort(key=lambda x: x[0])
sorted_lines.append(line)
assert([(25, 75), (74, 26)] in sorted_lines)
assert([(25, 25), (74, 74)] in sorted_lines)
def test_hough_line_peaks():
img = np.zeros((100, 150), dtype=int)
rr, cc = line(60, 130, 80, 10)
img[rr, cc] = 1
out, angles, d = tf.hough_line(img)
with expected_warnings(['`background`']):
out, theta, dist = tf.hough_line_peaks(out, angles, d)
assert_equal(len(dist), 1)
assert_almost_equal(dist[0], 80.723, 1)
assert_almost_equal(theta[0], 1.41, 1)
def test_hough_line_peaks_dist():
img = np.zeros((100, 100), dtype=np.bool_)
img[:, 30] = True
img[:, 40] = True
hspace, angles, dists = tf.hough_line(img)
with expected_warnings(['`background`']):
assert len(tf.hough_line_peaks(hspace, angles, dists,
min_distance=5)[0]) == 2
assert len(tf.hough_line_peaks(hspace, angles, dists,
min_distance=15)[0]) == 1
def test_hough_line_peaks_angle():
with expected_warnings(['`background`']):
check_hough_line_peaks_angle()
def check_hough_line_peaks_angle():
img = np.zeros((100, 100), dtype=np.bool_)
img[:, 0] = True
img[0, :] = True
hspace, angles, dists = tf.hough_line(img)
assert len(tf.hough_line_peaks(hspace, angles, dists,
min_angle=45)[0]) == 2
assert len(tf.hough_line_peaks(hspace, angles, dists,
min_angle=90)[0]) == 1
theta = np.linspace(0, np.pi, 100)
hspace, angles, dists = tf.hough_line(img, theta)
assert len(tf.hough_line_peaks(hspace, angles, dists,
min_angle=45)[0]) == 2
assert len(tf.hough_line_peaks(hspace, angles, dists,
min_angle=90)[0]) == 1
theta = np.linspace(np.pi / 3, 4. / 3 * np.pi, 100)
hspace, angles, dists = tf.hough_line(img, theta)
assert len(tf.hough_line_peaks(hspace, angles, dists,
min_angle=45)[0]) == 2
assert len(tf.hough_line_peaks(hspace, angles, dists,
min_angle=90)[0]) == 1
def test_hough_line_peaks_num():
img = np.zeros((100, 100), dtype=np.bool_)
img[:, 30] = True
img[:, 40] = True
hspace, angles, dists = tf.hough_line(img)
with expected_warnings(['`background`']):
assert len(tf.hough_line_peaks(hspace, angles, dists, min_distance=0,
min_angle=0, num_peaks=1)[0]) == 1
@test_parallel()
def test_hough_circle():
# Prepare picture
img = np.zeros((120, 100), dtype=int)
radius = 20
x_0, y_0 = (99, 50)
y, x = circle_perimeter(y_0, x_0, radius)
img[x, y] = 1
out1 = tf.hough_circle(img, radius)
out2 = tf.hough_circle(img, [radius])
assert_equal(out1, out2)
out = tf.hough_circle(img, np.array([radius], dtype=np.intp))
assert_equal(out, out1)
x, y = np.where(out[0] == out[0].max())
assert_equal(x[0], x_0)
assert_equal(y[0], y_0)
def test_hough_circle_extended():
# Prepare picture
# The circle center is outside the image
img = np.zeros((100, 100), dtype=int)
radius = 20
x_0, y_0 = (-5, 50)
y, x = circle_perimeter(y_0, x_0, radius)
img[x[np.where(x > 0)], y[np.where(x > 0)]] = 1
out = tf.hough_circle(img, np.array([radius], dtype=np.intp),
full_output=True)
x, y = np.where(out[0] == out[0].max())
# Offset for x_0, y_0
assert_equal(x[0], x_0 + radius)
assert_equal(y[0], y_0 + radius)
def test_hough_ellipse_zero_angle():
img = np.zeros((25, 25), dtype=int)
rx = 6
ry = 8
x0 = 12
y0 = 15
angle = 0
rr, cc = ellipse_perimeter(y0, x0, ry, rx)
img[rr, cc] = 1
result = tf.hough_ellipse(img, threshold=9)
best = result[-1]
assert_equal(best[1], y0)
assert_equal(best[2], x0)
assert_almost_equal(best[3], ry, decimal=1)
assert_almost_equal(best[4], rx, decimal=1)
assert_equal(best[5], angle)
# Check if I re-draw the ellipse, points are the same!
# ie check API compatibility between hough_ellipse and ellipse_perimeter
rr2, cc2 = ellipse_perimeter(y0, x0, int(best[3]), int(best[4]),
orientation=best[5])
assert_equal(rr, rr2)
assert_equal(cc, cc2)
def test_hough_ellipse_non_zero_posangle1():
# ry > rx, angle in [0:pi/2]
img = np.zeros((30, 24), dtype=int)
rx = 6
ry = 12
x0 = 10
y0 = 15
angle = np.pi / 1.35
rr, cc = ellipse_perimeter(y0, x0, ry, rx, orientation=angle)
img[rr, cc] = 1
result = tf.hough_ellipse(img, threshold=15, accuracy=3)
result.sort(order='accumulator')
best = result[-1]
assert_almost_equal(best[1] / 100., y0 / 100., decimal=1)
assert_almost_equal(best[2] / 100., x0 / 100., decimal=1)
assert_almost_equal(best[3] / 10., ry / 10., decimal=1)
assert_almost_equal(best[4] / 100., rx / 100., decimal=1)
assert_almost_equal(best[5], angle, decimal=1)
# Check if I re-draw the ellipse, points are the same!
# ie check API compatibility between hough_ellipse and ellipse_perimeter
rr2, cc2 = ellipse_perimeter(y0, x0, int(best[3]), int(best[4]),
orientation=best[5])
assert_equal(rr, rr2)
assert_equal(cc, cc2)
def test_hough_ellipse_non_zero_posangle2():
# ry < rx, angle in [0:pi/2]
img = np.zeros((30, 24), dtype=int)
rx = 12
ry = 6
x0 = 10
y0 = 15
angle = np.pi / 1.35
rr, cc = ellipse_perimeter(y0, x0, ry, rx, orientation=angle)
img[rr, cc] = 1
result = tf.hough_ellipse(img, threshold=15, accuracy=3)
result.sort(order='accumulator')
best = result[-1]
assert_almost_equal(best[1] / 100., y0 / 100., decimal=1)
assert_almost_equal(best[2] / 100., x0 / 100., decimal=1)
assert_almost_equal(best[3] / 10., ry / 10., decimal=1)
assert_almost_equal(best[4] / 100., rx / 100., decimal=1)
assert_almost_equal(best[5], angle, decimal=1)
# Check if I re-draw the ellipse, points are the same!
# ie check API compatibility between hough_ellipse and ellipse_perimeter
rr2, cc2 = ellipse_perimeter(y0, x0, int(best[3]), int(best[4]),
orientation=best[5])
assert_equal(rr, rr2)
assert_equal(cc, cc2)
def test_hough_ellipse_non_zero_posangle3():
# ry < rx, angle in [pi/2:pi]
img = np.zeros((30, 24), dtype=int)
rx = 12
ry = 6
x0 = 10
y0 = 15
angle = np.pi / 1.35 + np.pi / 2.
rr, cc = ellipse_perimeter(y0, x0, ry, rx, orientation=angle)
img[rr, cc] = 1
result = tf.hough_ellipse(img, threshold=15, accuracy=3)
result.sort(order='accumulator')
best = result[-1]
# Check if I re-draw the ellipse, points are the same!
# ie check API compatibility between hough_ellipse and ellipse_perimeter
rr2, cc2 = ellipse_perimeter(y0, x0, int(best[3]), int(best[4]),
orientation=best[5])
assert_equal(rr, rr2)
assert_equal(cc, cc2)
def test_hough_ellipse_non_zero_posangle4():
# ry < rx, angle in [pi:3pi/4]
img = np.zeros((30, 24), dtype=int)
rx = 12
ry = 6
x0 = 10
y0 = 15
angle = np.pi / 1.35 + np.pi
rr, cc = ellipse_perimeter(y0, x0, ry, rx, orientation=angle)
img[rr, cc] = 1
result = tf.hough_ellipse(img, threshold=15, accuracy=3)
result.sort(order='accumulator')
best = result[-1]
# Check if I re-draw the ellipse, points are the same!
# ie check API compatibility between hough_ellipse and ellipse_perimeter
rr2, cc2 = ellipse_perimeter(y0, x0, int(best[3]), int(best[4]),
orientation=best[5])
assert_equal(rr, rr2)
assert_equal(cc, cc2)
def test_hough_ellipse_non_zero_negangle1():
# ry > rx, angle in [0:-pi/2]
img = np.zeros((30, 24), dtype=int)
rx = 6
ry = 12
x0 = 10
y0 = 15
angle = - np.pi / 1.35
rr, cc = ellipse_perimeter(y0, x0, ry, rx, orientation=angle)
img[rr, cc] = 1
result = tf.hough_ellipse(img, threshold=15, accuracy=3)
result.sort(order='accumulator')
best = result[-1]
# Check if I re-draw the ellipse, points are the same!
# ie check API compatibility between hough_ellipse and ellipse_perimeter
rr2, cc2 = ellipse_perimeter(y0, x0, int(best[3]), int(best[4]),
orientation=best[5])
assert_equal(rr, rr2)
assert_equal(cc, cc2)
def test_hough_ellipse_non_zero_negangle2():
# ry < rx, angle in [0:-pi/2]
img = np.zeros((30, 24), dtype=int)
rx = 12
ry = 6
x0 = 10
y0 = 15
angle = - np.pi / 1.35
rr, cc = ellipse_perimeter(y0, x0, ry, rx, orientation=angle)
img[rr, cc] = 1
result = tf.hough_ellipse(img, threshold=15, accuracy=3)
result.sort(order='accumulator')
best = result[-1]
# Check if I re-draw the ellipse, points are the same!
# ie check API compatibility between hough_ellipse and ellipse_perimeter
rr2, cc2 = ellipse_perimeter(y0, x0, int(best[3]), int(best[4]),
orientation=best[5])
assert_equal(rr, rr2)
assert_equal(cc, cc2)
def test_hough_ellipse_non_zero_negangle3():
# ry < rx, angle in [-pi/2:-pi]
img = np.zeros((30, 24), dtype=int)
rx = 12
ry = 6
x0 = 10
y0 = 15
angle = - np.pi / 1.35 - np.pi / 2.
rr, cc = ellipse_perimeter(y0, x0, ry, rx, orientation=angle)
img[rr, cc] = 1
result = tf.hough_ellipse(img, threshold=15, accuracy=3)
result.sort(order='accumulator')
best = result[-1]
# Check if I re-draw the ellipse, points are the same!
# ie check API compatibility between hough_ellipse and ellipse_perimeter
rr2, cc2 = ellipse_perimeter(y0, x0, int(best[3]), int(best[4]),
orientation=best[5])
assert_equal(rr, rr2)
assert_equal(cc, cc2)
def test_hough_ellipse_non_zero_negangle4():
# ry < rx, angle in [-pi:-3pi/4]
img = np.zeros((30, 24), dtype=int)
rx = 12
ry = 6
x0 = 10
y0 = 15
angle = - np.pi / 1.35 - np.pi
rr, cc = ellipse_perimeter(y0, x0, ry, rx, orientation=angle)
img[rr, cc] = 1
result = tf.hough_ellipse(img, threshold=15, accuracy=3)
result.sort(order='accumulator')
best = result[-1]
# Check if I re-draw the ellipse, points are the same!
# ie check API compatibility between hough_ellipse and ellipse_perimeter
rr2, cc2 = ellipse_perimeter(y0, x0, int(best[3]), int(best[4]),
orientation=best[5])
assert_equal(rr, rr2)
assert_equal(cc, cc2)
if __name__ == "__main__":
np.testing.run_module_suite()