Hit detection on non-transparent pixel

Question

Given a PNG in a web context with some transparent pixels and some non-transparent pixels, is there a way in Javascript to determine if a user has clicked on a non-transpare

Answer 1

Canvas is the way to go for this purpose. But also remember that older internet explorer versions will not be capable of the getImageData() function. Even if you include excanvas.

I made a small jquery plugin exactly for this purpose, maybe it will help you solving your problem without to completely reinvent the wheel. http://www.cw-internetdienste.de/pixelselection/