1. A method for a printing system to print an image based on image data received from a source comprising: receiving the image data in a printer controller of the printing system; determining in the printer controller if the source of the image data is a secure or non-secure source; if the source is determined to be a non-secure source, printing the image using the image data as received; if the source is determined to be a secure source, modifying the image data in the printer controller to add a graphic security feature to the image data; and printing the image using the modified image data.