Image Display in HTML Page in Portal

I have an HTML page that displays an image from the database. It works fine when outside of a portal.

I want to put that HTML page in a portal but I cannot get it to display the image. I get the broken image symbol when I try to run it from inside the portal

The code that works is below. The input.property is the record ID of the record that I want to display and comes across from a stateless form that is used to open the page. I moved the stateless form and the HTML page into the portal and I did change the URL that I'm opening so that it is pointing to the page in the portal. The page in the portal does open and it does display all the text data I want to display (plus an embedded view), it just doesn't display the image.

<%property_num = input.property.toLong();

prop_rec = Properties_List [ID == property_num];

prop_name = prop_rec.Property_Name;

imagelnk = prop_rec.Roof_Map;

/* if (imagelnk != null)

{

imagelnk = imagelnk.replaceAll("/sharedBy/appLinkName/"," https://creator.zoho.com" + zoho.appuri);

imagelnk = imagelnk.replaceAll("viewLinkName","Properties_List_View");

imagelnk = imagelnk.replaceAll("fieldName","Roof_Map");

}

else

{

imagelnk = "";

}%>

Assuming that the appowner is jptest and the appname is propertytest, the portal URL is

https://jptest.zohocreator.com/portal/propertytest

Neither the form "Properties_List" nor the view "Properties_List_View" is in the portal. I don't want them to be in the portal because I maintain the Properties List. I could, of course, put a copy of the Properties_List_View in the portal if I had to (e.g., Properties_List_View_P).

What do I need to do to get the portal to display the image? As I say, the page works beautifully when it is not in the portal.