1 """Draw on top of an image"""

     2 

     3 from Tkinter import *

     4 import sys

     5 

     6 def main():

     7     filename = sys.argv[1]

     8     root = Tk()

     9     img = PhotoImage(file=filename)

    10     w, h = img.width(), img.height()

    11     canv = Canvas(root, width=w, height=h)

    12     canv.create_image(0, 0, anchor=NW, image=img)

    13     canv.pack()

    14     canv.bind('<Button-1>', blob)

    15     root.mainloop()

    16 

    17 def blob(event):

    18     x, y = event.x, event.y

    19     canv = event.widget

    20     r = 5

    21     canv.create_oval(x-r, y-r, x+r, y+r, fill='red', outline="")

    22 

    23 main()