CSS3 и jQuery эффект при наведении на картинку

<ul id="da-thumbs" class="da-thumbs">
    <li>
        <a href="#">
            <img src="images/1.jpg" />
            <div><span>Описание для картинки 1</span></div>
        </a>
    </li>
    <li>
        <!-- ... -->
    </li>
    <!-- ... -->
</ul>

.da-thumbs li {
    float: left;
    margin: 5px;
    background: #fff;
    padding: 8px;
    position: relative;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}
.da-thumbs li a,
.da-thumbs li a img {
    display: block;
    position: relative;
}
.da-thumbs li a {
    overflow: hidden;
}
.da-thumbs li a div {
    position: absolute;
    background: rgba(75,75,75,0.7);
    width: 100%;
    height: 100%;
}

this.$el.on( 'mouseenter.hoverdir, mouseleave.hoverdir', function( event ) {

    var $el = $( this ),
        $hoverElem = $el.find( 'div' ),
        direction = self._getDir( $el, { x : event.pageX, y : event.pageY } ),
        styleCSS = self._getStyle( direction );

    if( event.type === 'mouseenter' ) {

        $hoverElem.hide().css( styleCSS.from );
        clearTimeout( self.tmhover );

        self.tmhover = setTimeout( function() {

            $hoverElem.show( 0, function() {

                var $el = $( this );
                if( self.support ) {
                    $el.css( 'transition', self.transitionProp );
                }
                self._applyAnimation( $el, styleCSS.to, self.options.speed );

            } );


        }, self.options.hoverDelay );

    }
    else {

        if( self.support ) {
            $hoverElem.css( 'transition', self.transitionProp );
        }
        clearTimeout( self.tmhover );
        self._applyAnimation( $hoverElem, styleCSS.from, self.options.speed );

    }

} );