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)

while(1):
    cv2.imshow('image',img)
    if cv2.waitKey(20) & 0xFF == 27:
        break
cv2.destroyAllWindows()


'''
def draw_circle(event, x,y,flag, param):
    if event == cv2.EVENT_LBUTTONDBLCLK:
        cv2.circle(img,(x,y),100,(255,0,0),-1)

img = np.zeros((500,500,3), np.uint8)
cv2.namedWindow("image",cv2.WINDOW_NORMAL)
cv2.setMouseCallback('image',draw_circle)
while(1):
    cv2.imshow("image",img)
    cv2.waitKey(1)                   #<---- this code has problem here.
cv2.destroyAllWindows()
