There is a page with a large number of images. The images are set as a CSS style background looking like this:
<div style="background-image: url("http://test.com/abc123.jpg");">
The page loads, but sometimes, some images are not loaded. The URL is still set, the DIV has the correct size, only the image itself is not displayed. (This may be due to a browser, server or a network problem but that is not important here - we only want to know whether the image is loaded or not).
How can I check that a background image like this has been loaded?