Full Screen Background Image Is Stretched

Question

I had made a full screen background image for one of my clients, but the problem is that when I make the image to fit all the screen using the following css codes:

Answer 1

Since the questions doesn't specifically state CSS only (or NOT Javascript), here is a jQuery solution that I've worked out and have been using. I've noticed there might be an issue with mobile browsers.

//resize the background image
function resizeImage($selection){
    //get the ratio of the image
    var imageRatio = $selection.width() / $selection.height();

    //get the screen ratio
    var screenRatio = $(window).width() / $(window).height();

    //if the image is wider than the screen
    if(imageRatio > screenRatio){
        $selection.height($(window).height()); //set image height to screen height
        $selection.width($(window).height()*imageRatio); //set the correct width based on image ratio
    }

    //if the screen is wider than the image
    else{
        $selection.width($(window).width()); //set the image width to the screen width
        $selection.height($(window).width()/imageRatio); //set the correct image height based on the image ratio
    }
}

Run this whenever you want to resize the image, typically on "onresize" and "onload"