Method and apparatus for imprinting ID information into a digital content and for reading out the same

Abstract

After a digital content is loaded into an information terminal such as a PC, ID information unique to a viewer or a user of the PC is imprinted into the content. The ID information is imprinted into a predetermined location of the content or alternatively, it may be imprinted over the entire content in the form of a spatial frequency. The content with an ID added thereto is then enabled to be used in the terminal.

1 . A method for distributing a digital content on a computer network, said method comprising: 
 receiving via the computer network a request for a digital content from an information terminal, the request identifying the information terminal or a user thereof;    obtaining an encoded version of the digital content;    generating a decoding program such that ID information representing the information terminal or user is embedded therein, and wherein the decoding program is programmed to perform the function of decoding the encoded digital content at the information terminal to produce a decoded digital content having the ID information imprinted therein;    transmitting via the computer network the decoding program to the information terminal; and    transmitting via the computer network the encoded digital content to the information terminal in response to the request.    
   
   
       2 . The method of  claim 1 , wherein the ID information is imprinted into the decoded digital content over an extended portion of the decoded digital content.  
   
   
       3 . The method of  claim 2 , wherein the extended portion of the decoded digital content defines a content domain, and wherein the ID information is represented as a signal in a frequency domain associated with the content domain.  
   
   
       4 . The method of  claim 3 , wherein the frequency domain is a mapping of the content domain via an orthogonal transform, and wherein the ID information imprinting comprises: 
 inverse-transforming the frequency-domain representation of the ID information into a content-domain representation of the ID information via an inverse of the orthogonal transform; and    imprinting the inverse-transformed ID information into the loaded content.    
   
   
       5 . The method of  claim 4 , wherein the imprinting step comprises adding an offset to each of a plurality of data values of the content.  
   
   
       6 . The method of  claim 3 , wherein the ID information is imprinted into the decoded digital content in the form of reference information in the frequency domain.  
   
   
       7 . The method of  claim 1 , wherein the decoding program is programmed to also perform the function of enabling use of the decoded digital content at the information terminal only after imprinting the ID information.  
   
   
       8 . The method of  claim 1 , wherein the decoding program is a plug-in type program.  
   
   
       9 . The method of  claim 1 , wherein the decoding the encoded digital content to produce the decoded digital content having the ID information imprinted therein comprises simultaneously decoding the encoded content and imprinting a representation of the ID into the decoded content.  
   
   
       10 . A method for distributing a digital content on a computer network, said method comprising: 
 receiving via the computer network a request for a digital content from an information terminal, the request identifying the information terminal or a user thereof;    obtaining an encoded version of the digital content;    generating a decoding program such that ID information representing the information terminal or user is embedded therein, and wherein the decoding program is programmed to perform the function of decoding the encoded digital content at the information terminal to produce a decoded digital content having the ID information imprinted therein without additional explicit ID verification being performed at the information terminal by the user thereof;    transmitting via the computer network the decoding program to the information terminal; and    transmitting via the computer network the encoded digital content to the information terminal in response to the request.    
   
   
       11 . A method for distributing digital content, comprising: 
 receiving a request for digital content from an information terminal;    obtaining an encoded version of the digital content;    generating a decoding program that can concurrently decode the encoded digital content, read an identification code from the information terminal, and imprint the identification code on the digital content;    sending the encoded digital content and the decoding program together to the information terminal; and    concurrently decoding the encoded digital content, reading an identification code from the information terminal, and imprinting the identification code on the digital content at the information terminal.