An image data outputting apparatus and method form satisfactory images regardless of characteristics of an image forming apparatus by outputting copy forgery preventing image data for preventing copy-based forgery to the image forming apparatus. For example, a recording medium outputting system is constructed by connecting a LAN having a DB server managing transmission/reception of data to/from a database in the city office, and many LANs each having a terminal and a printer installed in a convenience store via a communication line and the Internet. Document data of a certificate is retrieved from the database in the city office by operating a terminal in a store, the retrieved document data is merged with copy forgery preventing image data corresponding to characteristics of a printer in the same store, and the merged data is outputted from the printer.