I've seen on a different post that its possible to change the px link here size of the background image but seems by default SP2013 will compress the image and make it 1024x768, the question is, can this be overridden by CSS?
1 Answer
There's a CSS3 property ('background-size') for sizing background images. SharePoint adds the background image class '.ms-backgroundImage' to the body tag. You can override that CSS.
Ex.
body.ms-backgroundImage { background-size: 400px 500px; background-position: center center; } The JavaScript way of doing it would be to get the background image url from the body tag and then dynamically create Img tag and then position it as fixed. This article describes such techniques. http://css-tricks.com/perfect-full-page-background-image/