Extract the dimension from an uploaded image URL in WordPress. Only works for images with the image size in the filename.

exctract-wordpress-image-size-from-url.php

/**
 * Extract the width and height from the URL of a resized image file in Wordpress.
 *
 * @param $url
 *
 * @return array|bool
 */
function exctract_wordpress_image_size_from_url($url) {
  preg_match('/-(?P<width>[0-9]+)x(?P<height>[0-9]+).(.+)$/', $url, $matches);
  if ( array_key_exists('width', $matches) && array_key_exists('width', $matches) ) {
    $width = $matches['width'];
    $height = $matches['height'];
    return compact('width', 'height');
  }
  return false;
}