title: find intersection point of two lines drawn using houghlines opencv
body: <p>How can I get the intersection points of lines down using opencv Hough lines algorithm?</p>
  
  <p>Here is my code:</p>
  
  <pre><code>import cv2
  import numpy as np
  import imutils
  
  im = cv2.imread('../data/test1.jpg')
  gray = cv2.cvtColor(im,cv2.COLOR_BGR2GRAY)
  edges = cv2.Canny(gray, 60, 150, apertureSize=3)
  
  img = im.copy()
  lines = cv2.HoughLines(edges,1,np.pi/180,200)
  
  for line in lines:
      for rho,theta in line:
          a = np.cos(theta)
          b = np.sin(theta)
          x0 = a*rho
          y0 = b*rho
          x1 = int(x0 + 3000*(-b))
          y1 = int(y0 + 3000*(a))
          x2 = int(x0 - 3000*(-b))
          y2 = int(y0 - 3000*(a))
          cv2.line(img,(x1,y1),(x2,y2),(0,255,0),10)
  
  cv2.imshow('houghlines',imutils.resize(img, height=650))
  cv2.waitKey(0)
  cv2.destroyAllWindows()
  </code></pre>
  
  <p>Output:</p>
  
  <p><a href="https://i.stack.imgur.com/I31Xz.png" rel="noreferrer"><img src="https://i.stack.imgur.com/I31Xz.png" alt="Output"></a></p>
  
  <p>I want to get all the points of intersection.</p>