How to save mouse position in variable using OpenCV and Python?

Question

I'm using Python and OpenCV for some vision application. I need to save mouse position in variables and I don't know how. I can get the current mouse position to print in window, but can't save it to variable.

My problem is similar to this one only I work in python: OpenCV Return value from mouse callback function

I define my function like this (for printing mouse position):

def mousePosition(event,x,y,flags,param):
    if event == cv2.EVENT_MOUSEMOVE:
        print x,y

I use it in my program like this:

cv2.setMouseCallback('Drawing spline',mousePosition)

Answer 1

Below is a small modified version of code from : http://docs.opencv.org/trunk/doc/py_tutorials/py_gui/py_mouse_handling/py_mouse_handling.html#mouse-handling

import cv2
import numpy as np

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

# 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)
    k = cv2.waitKey(20) & 0xFF
    if k == 27:
        break
    elif k == ord('a'):
        print ix,iy
cv2.destroyAllWindows()

It stores the mouse position in global variables ix,iy. Every time you double-click, it changes the value to new location. Press a to print the new value.