Chuanshuoge: opencv 23 hough transform

Wednesday, 24 March 2021

hough transform is applied after canny edge detection, lines are detected

canny edge

#main.py

import numpy as np

import cv2

cap = cv2.VideoCapture("assets/Tokyo night drive.mp4")

while True:

ret, frame = cap.read()

width = int(cap.get(3))

height = int(cap.get(4))

gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)

edges = cv2.Canny(gray, 254, 255, apertureSize=3)

lines = cv2.HoughLinesP(edges, 1, np.pi/180, 100, minLineLength=100, maxLineGap=10)

if not lines is None:

for line in lines:

x1, y1, x2, y2 = line[0]

cv2.line(frame, (x1, y1), (x2, y2), (0, 0, 255), 5)

cv2.imshow('frame', frame)

cv2.imshow('gray', gray)

cv2.imshow('canny edge', edges)

if cv2.waitKey(1) == ord('q'):

break

if cv2.waitKey(1) == ord('p'):

# wait until any key is pressed

cv2.waitKey(-1)

cap.release()

cv2.destroyAllWindows()

reference:

Chuanshuoge