Unable to display images in pdf

Unable to display images in pdf

Hello. 
I have an HTML page that is to be used as a "final report" to summarize details about a claim.
The result is intended to be emailed to employees and customers as a PDF.
 
I have included images that were attached to the claim by doing this:
  1. claim  =  Claim  [ID == input.Claim_ID.toLong()];
  2. claimPhotos = List();
  3. if ((claim.Image_1  !=  null)  &&  claim.Include_Image_1_In_Final_Report)
  4. {
  5.     photoHTML = claim.Image_1.replaceFirst("/sharedBy/appLinkName/",zoho.appuri);
  6.     photoHTML = photoHTML.replaceFirst("viewLinkName","Claim/" + input.Claim_ID);
  7.     photoHTML = photoHTML.replaceFirst("fieldName/image","Image_1/image-download");
  8.     claimPhotos.add(photoHTML);
  9. }
  10. ...

And then later I loop through the list and add the photoHTML to the page.
This works fine when I view it in the browser, but I can't seem to get the images to display in a pdf.

I tried to use a permalink by doing something like this:

  1. photoHTML = photoHTML.replaceFirst("viewLinkName","view-perma/Claim/HUEvTy8uRRWgRw.../" + input.Claim_ID);

... but that doesn't show the image at all. How can I get images to display in the PDF without making all the claim information publicly available?