title: TCPDF don't display image with writeHTML
body: <p>this question seems an evergreen on TCPDF...<br>
  I have an issue that's driving me crazy.</p>
  
  <p>I have an html code that I use as "template" for my PDF, here I have my company logo.<br>
  Everything works fine on localhost (Windows), but when I move online, the image is not shown.<br>
  Pay attention: I don't get any error (ie the <em>Unable to get image</em> error) on my PDF the image is simple blank!<br>
  Infact if I click on the PDF on the position where the images it's supposed to be, I can select it, and Adobe enables the option "Copy image".</p>
  
  <p>Obviously the image exists, is here, and permission are correct.<br>
  If I try to surf there, or view the generated HTML page, everything is fine.</p>
  
  <p>This is the PHP code:</p>
  
  <pre><code>$pdf-&gt;SetMargins($params-&gt;get('pdfMarginLeft', 15), $params-&gt;get('pdfMarginTop', 27), $params-&gt;get('pdfMarginRight', 15));
  $pdf-&gt;SetHeaderMargin(PDF_MARGIN_HEADER);
  $pdf-&gt;SetFooterMargin(PDF_MARGIN_FOOTER);
  
  $pdf-&gt;SetAutoPageBreak(TRUE, PDF_MARGIN_BOTTOM);
  
  $pdf-&gt;setImageScale(PDF_IMAGE_SCALE_RATIO);
  $pdf-&gt;SetFont('helvetica', '', 8);
  $pdf-&gt;AddPage();
  
  $pdf-&gt;writeHTML($html, true, false, true, false, '');
  
  $pdf-&gt;lastPage();
  </code></pre>
  
  <p>Then this is my HTML code (I just skipped everything except the image):</p>
  
  <pre><code>&lt;img alt="logo black" src="../images/logo_black.png" height="60" width="210" /&gt;
  </code></pre>
  
  <p>I've tried with the url (relative and absolute) and with the path (relative and absolute), the problem still occurs.
  Any ideas?</p>