import numpy as np
import cv2

cap = cv2.VideoCapture(0)
ret, frame = cap.read()

while(1):
    ret, frame = cap.read()

    gray = cv2.cvtColor(frame,cv2.COLOR_BGR2GRAY)
    edges = cv2.Canny(gray,50,150,apertureSize = 3)

    lines = cv2.HoughLines(edges,0.5,np.pi/180,200)
    if lines is not None :
      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(frame,(x1,y1),(x2,y2),(0,0,255),2)
    
    cv2.imshow('frame o',frame)
    k = cv2.waitKey(30) & 0xff
    if k == 27:
        break

cap.release()
cv2.destroyAllWindows()