公开(公告)号：CA2224019A1

公开(公告)日：1998-06-26

申请号：CA2224019

申请日：1997-12-05

Applicant: IBM

Inventor： KOIDE AKIO ,  MORIMOTO NORISHIGE ,  KOBAYASHI SEIJI ,  SHIMIZU SHUICHI

IPC: H04N1/387 ,  G06T1/00 ,  G09C5/00 ,  H04N1/32 ,  H04L9/14

Abstract: It is intended to make it possible to properly certify who is a genuine owner, a nd to inhibit deterioration of image quality of media information to which the embedding opera tion is performed by adaptively determining amount of the operation for characteristic v alues such as pixel values. The invention provides a data hiding method for embedding messa ge data into media data comprising the steps of obtaining a secondary key by inputting a key having a predetermined value to a specified function; determining hiding positio ns in which the message data will be embedded according to the obtained secondary key, and selecting one of plural hiding functions according to the secondary key so that the selected hiding function is used for each of the determined hiding positions; and embeddi ng the message data into each of the determined hiding positions according to the selec ted hiding function corresponding to the hiding position.

公开(公告)号：CA2264625A1

公开(公告)日：1998-04-23

申请号：CA2264625

申请日：1997-02-13

Applicant: IBM

Inventor： MORIMOTO NORISHIGE ,  MAEDA JUNJI

IPC: H04N7/08 ,  G06T1/00 ,  H04N7/00 ,  H04N7/081 ,  H04N7/16 ,  H04N5/76 ,  G11B23/00

Abstract: A method of hiding message information in media information in a frequency space. A high resistance to removal and alteration of hidden message is given. Even when signal processing is executed by using a frequency filter, the hidden message information is continuously maintained effectively. The frequency spectra (f1 and f2) of the medium information (M) and message information (m) are found by frequency-converting the information (m) and the information (M) in order to hide the message information (m) in media information (M). Then an area containing a characteristic frequency component indicating the feature of the message information (m) in a real space is extracted from the frequency spectrum (f2) of the message information (m) as a basic area (B). Then a frequency spectrum (f3) is generated as intermediate information by making n copies of the basic area (B), dispersedly arranging the copies in the frequency space and making the other frequency components zero. Lastly, the message information (m) is hidden in the medium information (M) by executing operation based on the frequency spectrum (f3) and medium information (M).