Vertically center Instagram caption on hover

jQuery(window).on('sbiafterimagesloaded', function (event) {

  $ = jQuery;

  $('.sbi_hover_top').each(function(){

	  var $self = $(this);

	  $self.css({

		'position' : 'absolute',

		'top' : ( $self.parent().height() - $self.height() ) / 2

	  });

	});

})