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copied!<p>you can use <a href="http://pypi.python.org/pypi/Polygon/2.0.4" rel="nofollow noreferrer">http://pypi.python.org/pypi/Polygon/2.0.4</a>, here is an example:</p> <pre><code>>>> import Polygon >>> a = Polygon.Polygon([(0,0),(1,0),(0,1)]) >>> b = Polygon.Polygon([(0.3,0.3), (0.3, 0.6), (0.6, 0.3)]) >>> a & b Polygon: <0:Contour: [0:0.60, 0.30] [1:0.30, 0.30] [2:0.30, 0.60]> </code></pre> <p>To convert the result of cv2.findContours to Polygon point format, you can:</p> <pre><code>points1 = contours[0].reshape(-1,2) </code></pre> <p>This will convert the shape from (N, 1, 2) to (N, 2)</p> <p>Following is a full example:</p> <pre><code>import Polygon import cv2 import numpy as np from scipy.misc import bytescale y, x = np.ogrid[-2:2:100j, -2:2:100j] f1 = bytescale(np.exp(-x**2 - y**2), low=0, high=255) f2 = bytescale(np.exp(-(x+1)**2 - y**2), low=0, high=255) c1, hierarchy = cv2.findContours((f1>120).astype(np.uint8), cv2.cv.CV_RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE) c2, hierarchy = cv2.findContours((f2>120).astype(np.uint8), cv2.cv.CV_RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE) points1 = c1[0].reshape(-1,2) # convert shape (n, 1, 2) to (n, 2) points2 = c2[0].reshape(-1,2) import pylab as pl poly1 = pl.Polygon(points1, color="blue", alpha=0.5) poly2 = pl.Polygon(points2, color="red", alpha=0.5) pl.figure(figsize=(8,3)) ax = pl.subplot(121) ax.add_artist(poly1) ax.add_artist(poly2) pl.xlim(0, 100) pl.ylim(0, 100) a = Polygon.Polygon(points1) b = Polygon.Polygon(points2) intersect = a&b # calculate the intersect polygon poly3 = pl.Polygon(intersect[0], color="green") # intersect[0] are the points of the polygon ax = pl.subplot(122) ax.add_artist(poly3) pl.xlim(0, 100) pl.ylim(0, 100) pl.show() </code></pre> <p>Output:</p> <p><img src="https://i.stack.imgur.com/mPx4I.png" alt="enter image description here"></p>

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