To make an image transparent in varying degrees, use the property opacity and filter property to work together in all browsers.

The lower value of opacity more transparent the image.

.transparent { opacity:0.3; filter:alpha(opacity=30); } <img class="transparent" src="image.jgp">

The property "opacity" takes values from "0.0" to "1.0".

The property "opacity" in "filter: alpha" takes values from 0 to 100.

This can be useful to set an image as the background faded, you create a page background, but do not bother to read the text on the page.

To put a very blurred image, put a small value for "opacity".

If we go back to normal to leave the image, that is, to remove the transparency, we put the maximum to both properties "opacity".

.normal { opacity:1.0; filter:alpha(opacity=100); }