Patent ID: 8218167

Claim:
An image output system comprising: a computer; and an image forming apparatus connected to the computer, wherein the computer includes: an output instruction receiving section which receives from a user an input of an image output instruction with respect to the image forming apparatus; an identification information receiving section which receives from a user an input of the user's unique identification information of the user; a transmitting section which transmits the image output instruction and the identification information respectively received by the output instruction receiving section and the identification information receiving section to the image forming apparatus; a receiving section which receives a password replied from the image forming apparatus in response to the identification information transmitted from the transmitting section to the image forming apparatus; and a display section which displays the password received by the receiving section, and the image forming apparatus includes: an electronic watermark information combining section which combines electronic watermark information with image data to be outputted; an output section which outputs image data to be outputted or image data which has been combined with the electronic watermark information by the electronic watermark information combining section; an identification information storage section which stores identification information for permission to output image data which is not combined with the electronic watermark information; an identification information receiving section which receives identification information transmitted from the transmitting section of the computer; a password generating section which generates a password different from the identification information if the identification information received by the identification information receiving section is stored in the identification information storage section; a password transmitting section which transmits the password generated by the password generating section to the computer; a password receiving section which receives input of a password from a user; and a controller which controls the output section to output image data which is not combined with the electronic watermark information by the electronic watermark information combining section in a case where the password received by the password receiving section matches with the password transmitted from the password transmitting section to the computer.