Set opacity of background image without affecting child elements

Question

Is it possible to set the opacity of a background image without affecting the opacity of child elements?

Example

All links in the footer need a custom bull

Answer 1

#footer ul li
     {
       position:relative;
       list-style:none;
     }
    #footer ul li:before
     {
       background-image: url(imagesFolder/bg_demo.png);
       background-repeat:no-repeat;
       content: "";
       top: 5px;
       left: -10px;
       bottom: 0;
       right: 0;
       position: absolute;
       z-index: -1;
       opacity: 0.5;
    }

You can try this code. I think it will be worked. You can visit the demo