ingozoell/hidpi-retina-detection.css

## hidpi-retina-detection.css
#hidpi { position: relative; display: none; z-index: 0;}

/* Hidpi/Retina Check
/* https://gist.github.com/sergejmueller/2642698 */
@media (-o-min-device-pixel-ratio: 5/4),
(-webkit-min-device-pixel-ratio: 1.25),
(min-resolution: 120dpi) {
	#hidpi { display: none;	position: relative; z-index: -1; }
}

## hidpi-retina-detection.html
<body>
<div id="hidpi"></div>
...
</body>

## hidpi-retina-detection.js
var $is_hidpi = false; // Global var
if( $('#hidpi').css('z-index') == '-1' ) {
    $is_hidpi = true;
}

$(document).ready(function() {
if(!$is_hidpi) {
  $('img').each(function(){
    $(this).removeAttr('width')
    $(this).removeAttr('height');
  });
}
});
	#hidpi { position: relative; display: none; z-index: 0;}

	/* Hidpi/Retina Check
	/* https://gist.github.com/sergejmueller/2642698 */
	@media (-o-min-device-pixel-ratio: 5/4),
	(-webkit-min-device-pixel-ratio: 1.25),
	(min-resolution: 120dpi) {
	#hidpi { display: none; position: relative; z-index: -1; }
	}
	var $is_hidpi = false; // Global var
	if( $('#hidpi').css('z-index') == '-1' ) {
	$is_hidpi = true;
	}

	$(document).ready(function() {
	if(!$is_hidpi) {
	$('img').each(function(){
	$(this).removeAttr('width')
	$(this).removeAttr('height');
	});
	}
	});