Patent ID: 8395792

Claim:
An image data processing apparatus used in a print system in which image data to be printed is transmitted from an image processing terminal to said image data processing apparatus on a network, and printing process is executed by an image forming apparatus when a print request command is issued from said image forming apparatus to said image data processing apparatus, comprising: a data storage unit storing image data received from said image processing terminal; a generating unit generating identification data enabling unique identification of said image data, based on said stored image data; an information storage unit storing said identification data in relation to user information identifying a user who requested printing process of the image data from which said identification data is derived and print information indicating whether or not printing has been done; and a control unit, upon reception of said image data from said image processing terminal, for generating the identification data from said image data, and if said generated identification data matches previously generated identification data which has been stored in said information storage unit and printing of the image data associated with the previously generated identification data has already been done, issuing alarm information to said image processing terminal so that an alarm is output on said image processing terminal.