WordPress Post Thumbnail - markhowellsmead/helpers GitHub Wiki

Aspect ratio

$post_thumbnail_atts = wp_get_attachment_image_src(get_post_thumbnail_id(), 'post_thumbnail');
$aspect_ratio = $post_thumbnail_atts[1] / $post_thumbnail_image_atts[2];
if ($aspect_ratio < 1) {
  $image_size = 'post_thumbnail_tall';
} elseif ($aspect_ratio === 1) {
  $image_size = 'post_thumbnail_square';
} else {
  $image_size = 'post_thumbnail_wide';
}