・コーナーを検出し矩形を描く



【Source Code】



# coding: UTF-8

import cv2

import numpy as np



img = cv2.imread('Hough.png')

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



ret,thresh = cv2.threshold(gray,50,255,0)

contours,hier = cv2.findContours(thresh,cv2.RETR_LIST,cv2.CHAIN_APPROX_SIMPLE)



 

for cnt in contours:

    if  cv2.contourArea(cnt)>5000:  # remove small areas like noise etc

        hull = cv2.convexHull(cnt)    # find the convex hull of contour

        hull = cv2.approxPolyDP(hull,0.1*cv2.arcLength(hull,True),True)

        print(hull)

        if len(hull)==4:

            cv2.drawContours(img,[hull],0,(0,255,0),2)



cv2.imshow('img',img)

cv2.waitKey(0)

cv2.destroyAllWindows()