WordPress - Create blur image

wordpress-blur-image.php

<?php
class WPMediaBlur {

	public function __construct() {
		$this->add_media_sizes();
		add_action( 'updated_post_meta', array( $this, 'post_updated' ), 10, 4 );
		add_action( 'added_post_meta', array( $this, 'post_updated' ), 10, 4 );
	}

	public function add_media_sizes() {
		add_image_size( 'blur', 350 );
	}

	public function post_updated($meta_id, $post_id, $meta_key, $meta_value) {
		if ('_wp_attachment_metadata' === $meta_key && in_array( $meta_value['sizes']['blur']['mime-type'], array( 'image/jpeg', 'image/png' ) ) ) {
			$path_image      = get_attached_file($post_id);
			$path_image      = ( ! empty( $path_image ) ) ? $path_image : '';
			$path_image_blur = dirname($path_image) . DIRECTORY_SEPARATOR . $meta_value['sizes']['blur']['file'];

			if ( file_exists( $path_image_blur ) ) {

				$gd_fn_imagecreatefrom = ( 'image/jpeg' === $meta_value['sizes']['blur']['mime-type'] ) ? 'imagecreatefromjpeg' : 'imagecreatefrompng';
				$gd_fn_image           = ( 'image/jpeg' === $meta_value['sizes']['blur']['mime-type'] ) ? 'imagejpeg' : 'imagepng';
				$image                 = $gd_fn_imagecreatefrom($path_image_blur);

				for ( $x = 1; $x <= 20; $x++ ) {
					@imagefilter($image, IMG_FILTER_GAUSSIAN_BLUR);
				}

				$gd_fn_image($image, $path_image_blur);

				@imagedestroy($image);
			}
		}
	}
}

new WPMediaBlur();