import cv2 as cv
import numpy as np

img = cv.imread('building.jpg')
gray = cv.imread('building.jpg', cv.IMREAD_GRAYSCALE)
edges = cv.Canny(gray,50,150,apertureSize = 3)	# 에지 검출
lines = cv.HoughLines(edges,1,np.pi/180,200)		# 허프 변환 수행

for line in lines[:30]:		# 검출된 선들을 영상 위에 표시
    rho,theta = line[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)

cv.imshow('Hough', img)
cv.imshow('Edges', edges)

cv.waitKey(0)
cv.destroyAllWindows()
