import cv2 as cv
import numpy as np

img = cv.imread('foto.jpg')
gray = cv.cvtColor(img,cv.COLOR_BGR2GRAY)
#edges = cv.Canny(gray,50,150,apertureSize = 3)
lines = cv.HoughLines(gray,1,np.pi,200)
print lines
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))

    cv.line(img,(x1,y1),(x2,y2),(0,0,255),2)
    print a
    print b

cv.imwrite('houghlines3.jpg',img)