plt.imshow(image, cmap=plt.cm.gray)
plt.title('Input image')
plt.subplot(122)
plt.imshow(np.log(1 + h),
extent=[np.rad2deg(theta[-1]), np.rad2deg(theta[0]),
d[-1], d[0]],
cmap=plt.cm.gray, aspect=1/1.5)
plt.title('Hough transform')
plt.xlabel('Angles (degrees)')
plt.ylabel('Distance (pixels)')
# Line finding, using the Probabilistic Hough Transform
image = data.camera()
edges = canny(image, 2, 1, 25)
lines = probabilistic_hough(edges, threshold=10, line_length=5, line_gap=3)
plt.figure(figsize=(12, 4))
plt.subplot(131)
plt.imshow(image, cmap=plt.cm.gray)
plt.title('Input image')
plt.subplot(132)
plt.imshow(edges, cmap=plt.cm.gray)
plt.title('Sobel edges')
plt.subplot(133)
plt.imshow(edges * 0)
def test_camera():
""" Test that "camera" image can be loaded. """
cameraman = data.camera()
assert_equal(cameraman.ndim, 2)
