First of all the link you provided is not an image. It outputs..
This XML file does not appear to have any style information associated with it. The document tree is shown below.
<Error>
<Code>AllAccessDisabled</Code>
<Message>All access to this object has been disabled</Message>
<RequestId>35DFBD44D75B45C4</RequestId>
<HostId>
n1TT+gOUuMJ3RydGND/s3QL73JJEadz/2uQutK4NNUDbEaGX6EI0Y8a/6eDHLR6H
</HostId>
</Error>
Tested & Works !
Below code reads an image from an URL, saves it and then opens/renders on browser.
<?php
$image ="http://blog.stackoverflow.com/wp-content/uploads/stackoverflow-logo-300.png";
$ch = curl_init($image);
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_BINARYTRANSFER,1);
$rawdata=curl_exec ($ch);
curl_close ($ch);
$fp = fopen("test.jpg",'w');
fwrite($fp, $rawdata);
fclose($fp);
header ("Content-Type: image/png");
readfile("test.jpg");
OUTPUT :
Or
If you want just to render it.. Do like this.
<?php
readfile("http://blog.stackoverflow.com/wp-content/uploads/stackoverflow-logo-300.png");
header ("Content-Type: image/png");