[Image-SIG] Creating a Transparent Image and Placing it Over Another Image (txt)

[Howard Lightstone]

Here is a *dumb* example of what I think you want.  It can be elaborated with 
crosshairs, ring sizing, etc.

import PIL
import Image
import ImageTk

class data:
    startx=0
    starty=0

def startmotioncallback(event):
    data.startx=event.x
    data.starty=event.y

    
def motioncallback(event):
    deltax=event.x-data.startx
    deltay=event.y-data.starty
    data.startx=event.x
    data.starty=event.y
    # should put some limits on where the cirle is moved
    # left as exercise.....
    data.cnv.move(data.ring,deltax,deltay)
    
def Demo(root):
    # resize window
    root.geometry('400x400+0+0')
    data.root=root
    # make a canvas
    cnv=Canvas(root)
    cnv.pack(expand=1,fill=BOTH)
    data.cnv=cnv
    img=Image.open('white dragon.png')  # some image you have.....
    data.img=ImageTk.PhotoImage(img)
    data.photo=cnv.create_image(0,0,image=data.img,anchor='nw')
    data.ring=cnv.create_oval((100,100,300,300))
    cnv.bind("<B1-Motion>",motioncallback)
    cnv.bind("<Button-1>",startmotioncallback)
    root.mainloop()
    

if __name__ == '__main__':

    root=Tk()
    Demo(root)