Can I apply CSS(3) filters ONLY on image sections?

Question

I have a full screen background image

.bg { 
    left: 0;
    min-height: 100%; 
    min-width: 100%; 
    position: fixed; 
    top: 0; 
    z-index: -1; 
}

and want to apply a CSS3 filter, personally I would like to use a blur effect, at the same position as my body

.container {
    margin: 0 auto; 
    width: 1000px;
}

Here's an example:

screenshot http://imageshack.us/a/img443/4976/j7qj.jpg

I want to write text over the blurred container.

Answer 1

http://jsfiddle.net/QvSng/6/

CSS

body {
    position: absolute;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
    background: url(http://lorempixel.com/420/255) no-repeat center center fixed;
    background-size: cover;
}
body:before {
    left: 0;
    right: 0;
    margin-left:auto;
    margin-right:auto;
    content: "";
    position: absolute;
    height: 100%;
    width: 500px;
    background: url(http://lorempixel.com/420/255)  no-repeat center center fixed;
    background-size: cover;
    z-index: -1;
    filter: blur(5px);
    -webkit-filter: blur(5px);
}

div {
    height: 100%;
    width: 450px;
    margin: 0 auto;
}