公开(公告)号：EP0852441A4

公开(公告)日：2003-01-15

申请号：EP97902686

申请日：1997-02-13

Applicant: IBM

Inventor： SHIMIZU SHUICHI ,  MORIMOTO NORISHIGE ,  KOBAYASHI MEI

IPC: G06T1/00 ,  G09C5/00 ,  H04N1/32 ,  H04N1/44 ,  H04N1/387

CPC classification number: H04N1/32203 ,  G06T1/0021 ,  G06T2201/0051 ,  G06T2201/0061 ,  G09C5/00 ,  H04N1/32208 ,  H04N1/32251 ,  H04N1/32309 ,  H04N21/23892 ,  H04N21/8358 ,  H04N2201/3233 ,  H04N2201/327

Abstract: A data hiding method for hiding message data in media data and a data extracting method for extracting message data hidden in the media data. In the data hiding method, the message data are dispersedly hidden in the media data so that no third person can alter the message data. Specifically, the array elements of a message array are dispersedly hidden in a media array based on a status value S designating a specific array element in the media array when the media data and message data are expressed as the media array and the message array, respectively. The hiding method includes (a) a step of determining the j-th (j≥0) status value Sj, (b) a step of determining the (j+1)-th status value Sj+1 based on the value Sj, the array element of the media array designated by the value Sj and the above-mentioned array element of the message array, and (c) a step of hiding data to be hidden in the array element of the media array designated by the value Sj+1.