resize img to 50% by itself

HTML

<div id="wrap">
        <img class="fake" src="http://lorempixel.com/200/200" />
        <div id="img_wrap">
            <img class="normal" src="http://lorempixel.com/200/200" />
        </div>
    </div>

CSS

#wrap {
    position: relative;
    float: left;
}

img {
  background: red;
}

#wrap img.fake {
    float: left;
    visibility: hidden;
    width: auto;
}

#img_wrap {
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
}

#img_wrap img.normal {
    width: 200%;
}