contours.py

import cv2
import numpy as np
import functions

def empty(a):
    pass

cv2.namedWindow("Parameters")
cv2.resizeWindow("Parameters",640,240)
cv2.createTrackbar("Threshold1","Parameters",47,255,empty)
cv2.createTrackbar("Threshold2","Parameters",45,255,empty)
cv2.createTrackbar("Area","Parameters",5000,30000,empty)


def getContours(img,imgContour):
    contours,hierarchy=cv2.findContours(img,cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_NONE)

    for cnt in contours:
        area=cv2.contourArea(cnt)
        areaMin=cv2.getTrackbarPos("Area","Parameters")
        if area>areaMin:
            cv2.drawContours(imgContour,cnt,-1,(255,0,255),7)
            peri=cv2.arcLength(cnt,True)
            approx=cv2.approxPolyDP(cnt, 0.02*peri, True)
            x,y,w,h=cv2.boundingRect(approx)
            cv2.rectangle(imgContour,(x,y),(x+w,y+h),(0,255,0),5)
            cv2.putText(imgContour, "Points: "+str(len(approx)),(x+w+20, y+20), cv2.FONT_HERSHEY_COMPLEX, 0.7,(0,255,0),2)
            cv2.putText(imgContour, "Area: "+str(int(area)),(x+w+20, y+45), cv2.FONT_HERSHEY_COMPLEX, 0.7,(0,255,0),2)



img=cv2.imread("shapes.jpg")
imgContour=img.copy()
imgBlur=cv2.GaussianBlur(img,(7,7),1)
imgGray=cv2.cvtColor(imgBlur, cv2.COLOR_BGR2GRAY)

threshold1=cv2.getTrackbarPos("Threshold1","Parameters")
threshold2=cv2.getTrackbarPos("Threshold2","Parameters")
imgCanny=cv2.Canny(imgGray,threshold1,threshold2)
kernel = np.ones((5, 5))
imgDil=cv2.dilate(imgCanny,kernel,iterations=1)

getContours(imgDil,imgContour)

imgStack=functions.stackimages(0.8,([img,imgCanny,imgGray],
                                    [imgDil,imgContour,imgDil]))

cv2.imshow("Staked Image",imgStack)

cv2.waitKey(0)