An Information Hiding Method Based on EMF Files Carrier

As a general file carrier, EMF (Enhanced Windows MetaFile) file has been widely used in printing industry, production of industrial symbol legend and document formats conversion, etc. This paper proposes an information hiding method based on EMF file parsing. First of all, it obtains all the objects and device environments by parsing the elements in the EMF file, then, watermark information is embedded by modifying the functions that is used to draw these objects, at last the modified GDI (graphics device interface) functions are saved into a new EMF file. This method can extend the application of EMF file in the areas of electronic documents protection and the audit on security printing of office documents.