WordPress - Remove the featured image from the content in feeds

wp-remove-featured-image.php

<?php
	/**
	 * Removes the "featured image" from the content
	 * Google news stand/Facebook Instant Articles do not like it
	 * Even different sizes of the Featured Image throw warnings
	 */
	function remove_featured_image_from_content( $content ) {

		// Get the post ID
		$post_ID	= get_the_ID();

		if ( has_post_thumbnail( $post_ID ) ) {

			// Get the featured image's data
			$image_ID		= get_post_thumbnail_id( $post_ID );
			$image_info		= wp_get_attachment_metadata( $image_ID );
			$upload_dir		= wp_upload_dir();
			$upload_folder	= $upload_dir['baseurl'];
			$image_date		= get_the_date( 'Y/m', $image_ID );

			// Check all the images of the post against the featured image and it's generated sizes
			if ( isset( $image_info['sizes'] ) ) {

				foreach ( $image_info['sizes'] as $image_size) {

					$file_name	= $upload_folder .'/'. $image_date .'/'. $image_size['file'];
					$file_name	= preg_quote($file_name, '/');

					// check if it's wrapped in a figure tag, then check for the image tag alone
					$content	= preg_replace( '/<figure.*?><img.*?src="('. $file_name .')".*?\>.*?<\/figure>/i', '', $content );
					$content	= preg_replace( '/<img.*?src="('. $file_name .')".*?\>/i', '', $content );

					// remove any empty anchor links that might have been left behind
					$content	= preg_replace( '/<a[^>]*><\/a>/', '', $content );

				}

			}
		}

		return $content;
	}
	add_filter( 'the_content_feed', 'remove_featured_image_from_content' );