add a image on whole page css code example

Example 1: css background image full screen responsive

html { 
  background: url(images/bg.jpg) no-repeat center center fixed; 
  -webkit-background-size: cover;
  -moz-background-size: cover;
  -o-background-size: cover;
  background-size: cover;
}

Example 2: bootstrap create full screen background image

.wrapper{background: url('/assets/64531/green_suburb.jpg') no-repeat   center center fixed;
-webkit-background-size: cover;
-moz-background-size: cover;
-o-background-size: cover;
background-size: cover;}