posting images into users feed with source is not working - facebook

Question

i am trying to create a fb app using the user profile pic. app will generate a new image that image should post to user feed. I am trying to use "source" but it is not working. This is not giving full image. It gives thumbnails instead of posting full image. Here is my code
$canvas = imagecreatetruecolor($crop_width,$crop_height);
imagecopy($canvas,$currentimage,0,0,0,0,$crop_width,$crop_height);
$test = $data['user_id'].'test.jpg';
imagejpeg($canvas, $test,100);
$new = imagecreatetruecolor(150,150);
imagecopyresized($new,$canvas,0,0,0,0,150,150,$w,$crop_height);
$resize1 = $data['user_id'].'resize1.jpg';
imagejpeg($new, $resize1 ,100);
$source1 = 'black.jpg';
$background = imagecreatefromjpeg($source1);
$resize = imagecreatefromjpeg($resize1);
imagecopy($background,$resize,100,250,0,0,150,150);
$output = $data['user_id'].'output.jpg';
imagejpeg($background,$output,100);
echo '<div align="center"><img src="'.$output.'"></div>';
unlink($test);
unlink($resize1);
$access_token = "ABCDEFGHIJKLM";
$graph_url ="https://graph.facebook.com/me/feed?access_token=".$access_token."&method=post&source=http://www.Google.es/images/srpr/nav_logo39.png&message=logo";
$user_permissions = json_decode(file_get_contents($graph_url));
print_r($user_permissions);
Please help me this solves me to create a perfect fb app.