Converter um array php para Javascript

Estou com dificuldade em converter um array php (dentro deste array possui outros arrays) para Javascript. O JS retorna cada caractere como um dado de uma gigantesca array.

O array em PHP está no formato a seguir:

Array
(

 [0] => Array
 (
 [popup] => [http://localhost/loja/image/cache/data/ipod_classic_4-900x900.jpg](http://localhost/loja/image/cache/data/ipod_classic_4-900x900.jpg)
 [thumb] => [http://localhost/loja/image/cache/data/ipod_classic_4-49x49.jpg](http://localhost/loja/image/cache/data/ipod_classic_4-49x49.jpg)
 [thumb1] => [http://localhost/loja/image/cache/data/ipod_classic_4-400x400.jpg](http://localhost/loja/image/cache/data/ipod_classic_4-400x400.jpg)
 [mobi] => [http://localhost/loja/image/cache/data/ipod_classic_4-310x310.jpg](http://localhost/loja/image/cache/data/ipod_classic_4-310x310.jpg)
 )

 [1] => Array
 (
 [popup] => [http://localhost/loja/image/cache/data/ipod_classic_3-900x900.jpg](http://localhost/loja/image/cache/data/ipod_classic_3-900x900.jpg)
 [thumb] => [http://localhost/loja/image/cache/data/ipod_classic_3-49x49.jpg](http://localhost/loja/image/cache/data/ipod_classic_3-49x49.jpg)
 [thumb1] => [http://localhost/loja/image/cache/data/ipod_classic_3-400x400.jpg](http://localhost/loja/image/cache/data/ipod_classic_3-400x400.jpg)
 [mobi] => [http://localhost/loja/image/cache/data/ipod_classic_3-310x310.jpg](http://localhost/loja/image/cache/data/ipod_classic_3-310x310.jpg)
 )

 [2] => Array
 (
 [popup] => [http://localhost/loja/image/cache/data/ipod_classic_2-900x900.jpg](http://localhost/loja/image/cache/data/ipod_classic_2-900x900.jpg)
 [thumb] => [http://localhost/loja/image/cache/data/ipod_classic_2-49x49.jpg](http://localhost/loja/image/cache/data/ipod_classic_2-49x49.jpg)
 [thumb1] => [http://localhost/loja/image/cache/data/ipod_classic_2-400x400.jpg](http://localhost/loja/image/cache/data/ipod_classic_2-400x400.jpg)
 [mobi] => [http://localhost/loja/image/cache/data/ipod_classic_2-310x310.jpg](http://localhost/loja/image/cache/data/ipod_classic_2-310x310.jpg)
 )

)

E o script está assim:

 <script type="text/javascript"><!--
 var images = '<?php echo json_encode($images); ?>';

 $(document).ready(function() {

 if(images) {
 console.log(images);
 for(i = 0; i < images.length; i++) {
 if(window.innerWidth > 768) {
 $(".image-additional").append('<a href="#" title="<?php echo $heading_title; ?>" data-image="'+ images[i].thumb +'" data-zoom-image="'+ images[i].popup +'"><img src="'+ images[i].thumb +'" title="<?php echo $heading_title; ?>" alt="<?php echo $heading_title; ?>" /></a>');
 } else {
 $(".image-additional").append('<a href="#" title="<?php echo $heading_title; ?>" data-image="'+ images[i].mobi +'" data-zoom-image="'+ images[i].popup +'"><img src="'+ images[i].thumb +'" title="<?php echo $heading_title; ?>" alt="<?php echo $heading_title; ?>" /></a>');
 }
 }
 }
 });
 --></script>