CHANGE - Regenerete Thumbnail Wordpress

gistfile1.php

<?php

// Process a single image ID (this is an AJAX handler)
function ajax_process_image() {
	@error_reporting( 0 ); // Don't break the JSON result

	header( 'Content-type: application/json' );

	$id = (int) $_REQUEST['id'];
	$image = get_post( $id );

	if ( ! $image || 'attachment' != $image->post_type || 'image/' != substr( $image->post_mime_type, 0, 6 ) ) {
		die( json_encode( array( 'error' => sprintf( __( 'Failed resize: %s is an invalid image ID.', 'regenerate-thumbnails' ), esc_html( $_REQUEST['id'] ) ) ) ) );
		return;
        }

	if ( ! current_user_can( $this->capability ) ) {
		$this->die_json_error_msg( $image->ID, __( "Your user account doesn't have permission to resize images", 'regenerate-thumbnails' ) );
		return;
        }

	$fullsizepath = get_attached_file( $image->ID );

	if ( false === $fullsizepath || ! file_exists( $fullsizepath ) ) {
		$this->die_json_error_msg( $image->ID, sprintf( __( 'The originally uploaded image file cannot be found at %s', 'regenerate-thumbnails' ), '<code>' . esc_html( $fullsizepath ) . '</code>' ) );
		return;
        }
        
	@set_time_limit( 900 ); // 5 minutes per image should be PLENTY
        
	// ############
	// DELETE ALL THUMBNAIL, TO REALLY REGENERETE =D
	// By: Pedro Elsner
	// ############
	global $_wp_additional_image_sizes;
	$imagePath = substr($fullsizepath, 0, strlen($fullsizepath) - 4);
	$imageFormat = substr($fullsizepath, -4);
	foreach($_wp_additional_image_sizes as $key => $value) {
		$thumb = $imagePath . '-' . $value['width'] . 'x' . $value['height'] . $imageFormat;
		unlink($thumb);
        }
	// ############
        
	$metadata = wp_generate_attachment_metadata( $image->ID, $fullsizepath );

	if ( is_wp_error( $metadata ) ) {
		$this->die_json_error_msg( $image->ID, $metadata->get_error_message() );
		return;
        }
	if ( empty( $metadata ) ) {
		$this->die_json_error_msg( $image->ID, __( 'Unknown failure reason.', 'regenerate-thumbnails' ) );
		return;
        }
        
	wp_update_attachment_metadata( $image->ID, $metadata );

	die( json_encode( array( 'success' => sprintf( __( '&quot;%1$s&quot; (ID %2$s) was successfully resized in %3$s seconds.', 'regenerate-thumbnails' ), esc_html( get_the_title( $image->ID ) ), $image->ID, timer_stop() ) ) ) );
}

?>