I need to know how the eyedropper tool of Chrome browser works without the need for canvas element and why can't we achieve it using javascript.
I have visited these two threads -
JavaScript eyedropper (tell color of pixel under mouse cursor)
Canvas eyeDropper
I have understood that if we need to implement it in our application, it can be done either using Canvas or using PHP in the server side. I need to know how does it internally works in Chrome browser without the need for canvas or without the cross domain restrictions.