<div class="hoverText">
     <span class="onHoverText"> Hello </span>
</div>

.hoverText
{
    display: none;
    position: absolute;
    text-align: center;
    font-size: 20px;
    top: 0%;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
}

.onHoverText
{
    position: absolute;
    top:50%;
}

$(".img-wrapper").mouseenter(function()
	{
	    $(this).parent().find(".hoverText").show();
   }).mouseleave(function()
   {
		$(this).parent().find(".hoverText").hide();
   });