Is it possible to get the height/width of an image that's not in the DOM?

Question

Is it possible to get the height and width of an image in the file system using JavaScript (i.e. an image that is not part of the DOM)? Or would I have to use JavaScript to inject the image into the DOM and grab the dimensions that way?

I ask because I'm writing a JavaScript method to render a UI component on the fly generated by Raphaël, which takes three image paths as part of the method parameters. These are then used to render the aforementioned UI component, and I need the dimensions of the images for positioning purposes.

Thanks in advance.

Answer 1

I think as long as the image has loaded you can grab the width and height - you shouldn't have to inject it into the DOM though. For example:

var tmp = new Image();
tmp.onload = function() {
    console.log(tmp.width + ' x ' + tmp.height);
}
tmp.src = 'http://cdn.sstatic.net/stackoverflow/img/sprites.png?v=4';

Answer 2

You cannot necessarily get to "the file system", but you can do this:

v = new Image();
v.onload = function() {
  alert("size: " + String(v.width) + 'x' + String(v.height));
};
v.src = "http://www.gravatar.com/avatar/96269f5a69115aa0e461b6334292d651?s=32&d=identicon&r=PG";

Would you count that as "adding to the DOM"?