| 摘要 |
PROBLEM TO BE SOLVED: To provide an image forming apparatus and an image forming method which can embed additional information in a predetermined condition irrespective of a change in resolution so that the additional information to be embedded into image data for forgery prevention can be securely deciphered. SOLUTION: A CPU 302 receives information unique to an engine 215 stored in an EEPROM 213, and outputs information 352 to a coding circuit 305. After ciphering of the information 352 in the circuit 305 and check of parities in a parity check circuit 306, the CPU 302 sets a preset value corresponding to each resolution mode to a main scanning counter 307 and a sub-scanning counter 308. The counters 307 and 308 send ON in an add-on line in accordance with a clock signal. An add-on dot generating circuit 309 generates an add-on dot and sends the generated add-on dot to an add-on additional processing section 205, and the add-on dot is embedded in an image. COPYRIGHT: (C)2005,JPO&NCIPI |
