Using tag in html does not work when calling an api

I want to run all calls outside of my web service through my website much like a proxy. Currently I call the proxy like this http://localhost/proxy?url=http://www.somewebsite.com/ .

My problem lies when I want to route all resources through the proxy. Currently I add a base tag to the html page like so,

<base href = "http://localhost/proxy?url=http://www.somewebsite.com/" />

in order to call the image at http://ift.tt/2fvaUeB like so,

<img src = "someimage.jpeg" >

This doesn't work and tries to get the image from http:localhost/someimage.jpeg

Is there a way to make the base tag work or have some other technique.