75 lines
2.1 KiB
Python
75 lines
2.1 KiB
Python
"""
|
|
usage: python hough_skimage.py file.png
|
|
|
|
find lines present in an image using scikit-image's hough transform.
|
|
"""
|
|
|
|
import sys
|
|
import time
|
|
|
|
import cv2
|
|
import numpy as np
|
|
from scipy.misc import imread
|
|
import matplotlib.pyplot as plt
|
|
from skimage.transform import hough_line, hough_line_peaks
|
|
|
|
|
|
def timeit(func):
|
|
def timed(*args, **kw):
|
|
start = time.time()
|
|
result = func(*args, **kw)
|
|
end = time.time()
|
|
print 'Function: %r took: %2.4f seconds' % (func.__name__, end - start)
|
|
return result
|
|
return timed
|
|
|
|
|
|
@timeit
|
|
def main():
|
|
image = cv2.imread(sys.argv[1])
|
|
print "image dimensions -> {0}".format(image.shape)
|
|
ret, binary = cv2.threshold(image, 127, 255, cv2.THRESH_BINARY)
|
|
binary = np.min(binary, axis=2)
|
|
binary = np.where(binary == 255, 0, 255)
|
|
rows, cols = binary.shape
|
|
pixel = np.zeros(binary.shape)
|
|
|
|
fig, ax = plt.subplots(1, 1, figsize=(8,4))
|
|
ax.imshow(image, cmap=plt.cm.gray)
|
|
|
|
theta_in = np.linspace(0, np.pi / 2, 10)
|
|
h, theta, d = hough_line(binary, theta_in)
|
|
for _, angle, dist in zip(*hough_line_peaks(h, theta, d)):
|
|
x0 = dist * np.cos(angle)
|
|
y0 = dist * np.sin(angle)
|
|
x1 = int(x0 + 1000 * (-np.sin(angle)))
|
|
y1 = int(y0 + 1000 * (np.cos(angle)))
|
|
x2 = int(x0 - 1000 * (-np.sin(angle)))
|
|
y2 = int(y0 - 1000 * (np.cos(angle)))
|
|
ax.plot((x1, x2), (y1, y2), '-r')
|
|
a = np.cos(angle)
|
|
b = np.sin(angle)
|
|
x = np.arange(binary.shape[1])
|
|
y = np.arange(binary.shape[0])
|
|
x = a * x
|
|
y = b * y
|
|
R = np.round(np.add(y.reshape((binary.shape[0], 1)), x.reshape((1, binary.shape[1]))))
|
|
pixel += np.isclose(R, np.round(dist))
|
|
|
|
pixel = np.clip(pixel, 0, 1)
|
|
pixel = np.where(pixel == 1, 0, 1)
|
|
binary = np.where(binary == 0, 255, 0)
|
|
binary *= pixel.astype(np.int64)
|
|
ax.imshow(binary, cmap=plt.cm.gray)
|
|
ax.axis((0, cols, rows, 0))
|
|
ax.set_title('Detected lines')
|
|
ax.set_axis_off()
|
|
ax.set_adjustable('box-forced')
|
|
plt.show()
|
|
|
|
|
|
if __name__ == '__main__':
|
|
if len(sys.argv) == 1:
|
|
print __doc__
|
|
else:
|
|
main() |