<?php 
$url = rt_get_option('frontpage_image_link_url', '#');
$target = (rt_get_option('frontpage_image_link_new_tab', false))? '_blank' : '';    
?>

<section id="frontpage-image" class="frontpage-section has-global-padding">   
    <div class="site-container">

        <?php if($url): ?>
            <a href="<?php echo esc_url($url) ?>" target="<?php echo esc_attr($target) ?>">
        <?php endif ?>  

        <div class="rt-img text-center">
            <?php echo wp_get_attachment_image(rt_get_option('frontpage_image'), 'full'); ?>
        </div>

        <?php if($url): ?>
            </a>
        <?php endif ?>

    </div>
</section>