Hi Zaghman,
if you follow your option 1, you can get a reference of the image either by "inspecting" the event parameter that you named "oControlEvent" or by going via the sap.ui.getCore().byId() function. (In addition you could try if "this" works too, but I'm not sure...)
In your example, all event handlers have a reference to the local variable "img". And after the for loop is finished, "img" points to the last image.
Regards, Frank