import cv2
import numpy as np

# mouse callback function
def draw_circle(event,x,y,flags,param):
    if event == cv2.EVENT_LBUTTONDBLCLK:
        cv2.circle(img,(x,y),100,(255,0,0),-1)

# Create a black image, a window and bind the function to window
img = np.zeros((512,512,3), np.uint8)
cv2.namedWindow('image')
cv2.setMouseCallback('image',draw_circle)
pts = np.array([[10,5],[20,30],[70,20],[50,10]], np.int32)
pts = pts.reshape((-1,1,2))
font = cv2.FONT_HERSHEY_SIMPLEX
while(1):
    cv2.line(img,(0,0),(511,511),(255,0,0),5)
    cv2.rectangle(img,(384,0),(510,128),(0,255,0),3)
    cv2.circle(img,(447,63), 63, (0,0,255), -1)
    cv2.ellipse(img,(256,256),(100,50),0,0,180,255,-1)
    cv2.polylines(img,[pts],True,(0,255,255))
    cv2.putText(img,'OpenCV',(10,500), font, 4,(255,255,255),2,255)
    
    cv2.imshow('image',img)
    if cv2.waitKey(20) & 0xFF == 27:
        break
cv2.destroyAllWindows()