filter

add_filter('get_image_tag', 'add_image_frames', 10, 6);
function add_image_frames($html, $id, $alt, $title, $align, $size) {
    list($img_src, $width, $height) = image_downsize($id, $size);
    $class = 'align' . esc_attr($align) .' size-' . esc_attr($size) . ' wp-image-' . $id;
    $class = apply_filters('get_image_tag_class', $class, $id, $align, $size);
    $before = '<div class="image_frame align'.$align.' size-'.$size.'"><div style="background-image: url(\'' . esc_attr($img_src) . '\');"><span>';
    $after = '</span></div></div>';
    $html = $before . $html . $after;
    return $html;
}