getContours.py

import cv2
import numpy as np

def getContours(img,imgContour):
    contours, hierarchy = cv2.findContours(img, cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_NONE)
    for cnt in contours:
        area = cv2.contourArea(cnt)
        #print(area)
        if area>500:
            cv2.drawContours(imgContour, cnt, -1,(255,0,0),3)
            peri = cv2.arcLength(cnt,True)
            #print(peri)
            approx = cv2.approxPolyDP(cnt,0.02*peri,True)
            #print(len(approx))
            objCor = len(approx)
            x, y, w, h = cv2.boundingRect(approx)

            if objCor == 3:
                objectType = "Triangle"
            elif objCor == 4:
                aspRatio = w/float(h)
                if aspRatio > 0.95 and aspRatio < 1.05:
                    objectType = "Square"
                else:
                    objectType = "Rectangle"
            elif objCor > 4:
                objectType = "Circle"
            else: objectType="None"

            cv2.rectangle(imgContour,(x,y),(x+w,y+h),(0,255,0),2)
            cv2.putText(imgContour,objectType, (x+(w//2)-10,y+(h//2)-10),cv2.FONT_HERSHEY_COMPLEX,0.5,(0,255,255),2)