title: How to detect Contour intersection in opencv python
body: <p>I am using the opencv python interface (not cv2)</p>
  
  <pre><code>contourmov =  cv.FindContours(image1, storage, cv.CV_RETR_CCOMP, cv.CV_CHAIN_APPROX_SIMPLE)
  contourmove = cv.FindContours(image2, storage, cv.CV_RETR_CCOMP, cv.CV_CHAIN_APPROX_SIMPLE)
  </code></pre>
  
  <p>I have the contours from image1 and image2 and I need the intersection between the two contours. </p>
  
  <p>I used </p>
  
  <pre><code>image3 = cv.CloneImage(image1)
  cv.Set(image1, cv.Scalar(0,0,0));
  image4 = cv.CloneImage(image1)
  cv.Set(image2, cv.Scalar(0,0,0));
  cv.DrawContours(image3,contourmov,cv.CV_RGB(0,255,0),cv.CV_RGB(0,255,0),1)
  cv.DrawContours(image4,contourmove,cv.CV_RGB(0,255,0),cv.CV_RGB(0,255,0),1)
  cv.And(image3,image4,image3)
  </code></pre>
  
  <p>So I assumed image3 will have the intersection of contours of image1 and image2 but i do not see them. </p>
  
  <p>Kindly let me know where am I going wrong.</p>