53 lines
1.4 KiB
Python
53 lines
1.4 KiB
Python
"""
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usage: python hough_opencv.py file.png
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find lines present in an image using opencv's hough transform.
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"""
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import sys
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import time
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import cv2
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import numpy as np
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import matplotlib.pyplot as plt
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def timeit(func):
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def timed(*args, **kw):
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start = time.time()
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result = func(*args, **kw)
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end = time.time()
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print 'Function: %r took: %2.4f seconds' % (func.__name__, end - start)
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return result
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return timed
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@timeit
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def main():
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image = cv2.imread(sys.argv[1])
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print "image dimensions -> {0}".format(image.shape)
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gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
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edges = cv2.Canny(gray, 50, 150, apertureSize=3)
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lines = cv2.HoughLines(edges, 1, np.pi / 180, 200)
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print "found {0} lines".format(len(lines))
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for line in lines:
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r, theta = line[0]
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# filter horizontal and vertical lines
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if theta == 0 or np.isclose(theta, np.pi / 2):
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x0 = r * np.cos(theta)
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y0 = r * np.sin(theta)
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x1 = int(x0 + 10000 * (-np.sin(theta)))
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y1 = int(y0 + 10000 * (np.cos(theta)))
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x2 = int(x0 - 10000 * (-np.sin(theta)))
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y2 = int(y0 - 10000 * (np.cos(theta)))
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cv2.line(image, (x1, y1), (x2, y2), (0, 0, 255), 5)
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plt.imshow(image)
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plt.show()
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if __name__ == '__main__':
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if len(sys.argv) == 1:
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print __doc__
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else:
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main() |