Black and White Image

Written by Bill EricksonPublished on June 19, 2012Updated on December 5, 2018

	<?php

	/**
	* Black and White Image
	* @url http://ottopress.com/2011/customizing-wordpress-images/
	*
	* @param array $meta
	* @return array $meta
	*/
	function be_bw_filter($meta) {
	$file = wp_upload_dir();
	if( isset( $meta['sizes']['be-subpage-bw']['file'] ) )
	$file = trailingslashit($file['path']).$meta['sizes']['be-subpage-bw']['file'];
	else
	$file = trailingslashit( $file['basedir'] ) . $meta['file'];
	list($orig_w, $orig_h, $orig_type) = @getimagesize($file);
	$image = wp_load_image($file);
	imagefilter($image, IMG_FILTER_GRAYSCALE);
	switch ($orig_type) {
	case IMAGETYPE_GIF:
	imagegif( $image, $file );
	break;
	case IMAGETYPE_PNG:
	imagepng( $image, $file );
	break;
	case IMAGETYPE_JPEG:
	imagejpeg( $image, $file );
	break;
	}
	return $meta;
	}
	add_filter('wp_generate_attachment_metadata','be_bw_filter');