import cv2 as cv
import numpy as np

def line_detection(image):
    gray = cv.cvtColor(image, cv.COLOR_BGR2GRAY)
    edges = cv.Canny(gray, 50, 150, apertureSize=3)
    lines = cv.HoughLines(edges, 1, np.pi/180, 200)#半径步长为1，每次偏转1度，直线最小长度200
    for line in lines:
        #print(type(lines))
        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(image, (x1, y1), (x2, y2), (0, 255, 0), 2)
    cv.imshow("line_detection", image)

def line_detect_possible_demo(image):
    gray = cv.cvtColor(image, cv.COLOR_BGR2GRAY)
    edges = cv.Canny(gray, 50, 150, apertureSize=3)
    lines = cv.HoughLinesP(edges, 1, np.pi/180, 100, minLineLength=100, maxLineGap=15)
    for line in lines:
        #print(type(line))
        x1, y1, x2, y2 = line[0]
        cv.line(image, (x1, y1), (x2, y2), (0, 0, 255), 2)
    cv.imshow("line_detect_possible_demo", image)

src = cv.imread("1.png")
src1=src.copy()
src2=src.copy()

cv.namedWindow("input image", cv.WINDOW_AUTOSIZE)
cv.imshow("input image", src)

line_detection(src1)
line_detect_possible_demo(src2)
cv.waitKey(0)

cv.destroyAllWindows()