echo part of a json code

echo part of a json code

I'm using imgur API to upload an image and then I'd like to echo the link
of the image. Here is the code:
<?php
$client_id = 'xxxxxxxxxxx';
$file = file_get_contents("http://mywebsite.com/image.jpeg");
$url = 'https://api.imgur.com/3/image.json';
$headers = array("Authorization: Client-ID $client_id");
$pvars = array('image' => base64_encode($file));
$curl = curl_init();
curl_setopt_array($curl, array(
CURLOPT_URL=> $url,
CURLOPT_TIMEOUT => 30,
CURLOPT_POST => 1,
CURLOPT_RETURNTRANSFER => 1,
CURLOPT_HTTPHEADER => $headers,
CURLOPT_POSTFIELDS => $pvars
));
$json_returned = curl_exec($curl); // blank response
echo $json_returned;
curl_close ($curl);
?>
The json_returned is something like this:
{"data":{"id":"93MubeE","title":null,"description":null,"datetime":1376842908,"type":"image\/jpeg","animated":false,"width":2197,"height":1463,"size":70884,"views":0,"bandwidth":0,"favorite":false,"nsfw":null,"section":null,"deletehash":"bk5k8HrAeH8aOtW","link":"http:\/\/i.imgur.com\/93MubeE.jpg"},"success":true,"status":200}
How can I echo image's url only? Thank you!