Envía varias imágenes en un objeto json en una sola peticion

req.php

<?php
	
	require('ImageToBase64.php');
	
	@$req = $_GET['req'];

	switch ($req){
	
		case "test":
		
			$r = array();
			$r['imgList']['imagen1']=imgGetData("./../image/0.png");
			$r['imgList']['imagen2']=imgGetData("./../image/0.jpg");
			$r['imgList']['imagen3']=imgGetData("./../image/0.gif");
			header('Content-Type: application/json');
			echo json_encode($r);
			break;
		case "background":
			echo json_encode(imgGetData('./../image/background.jpg'));
			break;
		
	}

?>