| 摘要 |
PROBLEM TO BE SOLVED: To prevent forgery of paper monies and illegal copies of a literary work by generating a hidden pattern with a set size and imbedding it into a print image, while reducing the size of the hidden pattern to the utmost. SOLUTION: A driver 5 of a host computer 1 is provided with a print data generating section 8 that generates print data fed to a printer 2, a hidden pattern generating section 9 that generates a hidden pattern to be imbedded into the print data, and an imbed discrimination section 10 that discriminates whether or not the hidden pattern generating section 9 generates a hidden pattern based on the result of analysis by a graphic device interface(GDI) module 6. Then the size of the hidden pattern is decided, so that part of the hidden pattern imbedded in a print image is included within a reference area set into the print image. In this case, the driver 5 automatically sets the size of the hidden pattern, in response to a size of a print image, whose print is instructed by an application program 4. |
