title: Houghlines no detect all lines opencv+python
body: <p>I really need help, I'm trying for many days know, how to use the houghlines function of OpenCV with python .</p>
  
  <p>The function does not detect all lines, even when the result of threshold if it's showing. I have some images and the portion of code that I'm using. thank you very much for any help. i'm sorry for my english.</p>
  
  <pre><code>    blur = cv2.GaussianBlur(mask,(5,5),0)
      ret,edges = cv2.threshold(mask,0,255,cv2.THRESH_BINARY+cv2.THRESH_OTSU)
      kernel = np.ones((3,3),np.uint8)
      image = cv2.erode(edges,kernel,iterations = 1)
  
      lines = cv2.HoughLines(image,1,np.pi/180,105)
      for rho,theta in lines[0]:
          a = np.cos(theta)
          b = np.sin(theta)
          x0 = a*rho
          y0 = b*rho
          x1 = int(x0 + 1000*(-b))
          y1 = int(y0 + 1000*(a))
          x2 = int(x0 - 1000*(-b))
          y2 = int(y0 - 1000*(a))
          cv2.line(img,(x1,y1),(x2,y2),(0,0,255),1)
  </code></pre>
  
  <p>Resulting imagen <a href="https://www.dropbox.com/s/9qd32mhrfjvplsn/Captura%20de%20pantalla%20de%202015-01-14%2009%3A46%3A46.png?dl=0" rel="nofollow">here</a></p>
  
  <p>Threshold image <a href="https://www.dropbox.com/s/mww4b1joyl1xdao/Captura%20de%20pantalla%20de%202015-01-14%2009%3A47%3A06.png?dl=0" rel="nofollow">here</a></p>