How to dim an image keeping transparency untouched with CSS or JS?

Question

Normal approach to dimming an image suggested everywhere is to change it\'s opacity attribute and display something dark under it. However, my image has transparency and is on w

Answer 1

There is a relatively new CSS property filter which might achieve what you are after.

The brightness option seems to be what you are after.

EDIT - Added interim support for FF via URL

JSFiddle Demo (with brightness and contrast options)

CSS

img {
width:250px;
}
#one:hover {
    -webkit-filter:brightness(50%);
    -moz-filter:brightness(50%);
    filter: url(#brightness); /* required for FF */
    filter:brightness(50%);
}
#two:hover {
    -webkit-filter:contrast(50%);    
    -moz-filter:contrast(50%);
     filter: url(#contrast);
    filter:contrast(50%);
}

MDN on Filter

Support is non-IE see CanIUse.com

FF support (at the time of writing) requires definition of an SVG filter

Brightness @ 50%

Contrast @ 200%