<style type="text/css">
.text_encima {
	position: absolute;
	/*mover texto derecha*/
	left:20px;
	/*mover texto abajo*/
	top:20px;
	color: #00b32d;
	font-size: 10px;
	font-family: arial;
}
</style>
<div id="content_img">
<span class="text_encima">Texto texto texto</span><img src="../img/ilusion.jpg">
</div>