What I am trying to do is something like this:

I have my image at <http://xyz.com/upload/image.jpg>.

And I am trying to display it in a PDF generated at <http://xyzsolution.com/mypdf.php>.
While generating PDF I am getting error as

TCPDF ERROR: [Image] Unable to get image: imagepath

My code to display image in PDF is as follows :

$this->Image('http://xyz.com/upload/image.jpg', 0, 0, 30, '', 'JPG', '', 'T', false, 300, '', false, false, 0, false, false, false);