Controlling the size of graphics in custom reports

Hi,

I'm building a report that will run on models. The report will simply show the model diagram (graphic). The problem is that if the diagram's size is big, the report automatically reduces the size to fit into the page. The behavior that I want is to keep the original diagram's size and instead to increase the size of the page. Similar to the behavior of the built-in report (Export to PDF).

Any help is highly appreciated.