Showing retina display image with pure css

Question

I have a situation where I can\'t possibly know the dimensions of an image (a proprietary limited cms...)

I need to figure out how to show a retina level image, and

Answer 1

Having thought about this issue myself - how about just using the x2 image and making sure to set the image's pixel dimensions? Retina displays will show it 1:1, and non-retina displays will show it at 50%. All clients have to load the x2 version though, meaning more traffic.