In one of the projects, it was required to track the number of times an image (which linked to another page) was clicked using Google Analytics. We found a very informative article here. It talks about tracking external links and file downloads. This wasn’t exactly our purpose, but the javascript downloaded from there acted as a very good starting point.

What we did was to add a code block like this after line no. 13 of the javascript code from the link given above.

var imgs = document.getElementsByTagName("img");
for(var l=0; l <imgs.length; l++) {
       try {
               var path = imgs[l].getAttribute('src');
               var isDoc = path.match(/\.(?:jpg|png|gif|svg)($|\&|\?)/);
               startListening(imgs[l],"click", trackImageClicks);
       }
       catch(e){
           continue;
       }
    }

And a method before the Analytics script provided by Google for the site

function trackImageClicks(evnt) {
    var e = (evnt.srcElement) ? evnt.srcElement : this;
    var lnk = (e.getAttribute("src").charAt(0) == "/") ? e.getAttribute("src") : "/" + e.getAttribute("src");
    if (typeof(pageTracker) == "object") pageTracker._trackPageview(lnk);
    while (e.tagName != "A") {
        e = e.parentNode;
    }
     lnk = (e.pathname.charAt(0) == "/") ? e.pathname : "/" + e.pathname;
    if (e.search && e.pathname.indexOf(e.search) == -1) lnk += e.search;
    if (e.hostname != location.host) lnk = e.hostname + lnk;
    if (typeof(pageTracker) == "object") pageTracker._trackPageview(lnk);
}

Now, the clicks on each image were getting tracked.