公开(公告)号：JP2003169207A

公开(公告)日：2003-06-13

申请号：JP2002079670

申请日：2002-03-20

Applicant: KOREA ELECTRONICS TELECOMM

Inventor： JOO SANGHYUN ,  SEO YONG-SEOK ,  SUH YOUNG HO

IPC: H04N7/24 ,  G06T1/00 ,  H04N1/32 ,  H04N1/387 ,  H04N7/08 ,  H04N7/081

Abstract: PROBLEM TO BE SOLVED: To provide an apparatus and method for embedding and extracting digital watermarks based on wavelets which is robust to external attacks while being capable of minimizing a degradation in picture quality caused by embedding of the watermarks. SOLUTION: The embedded watermarks embedded in DC component domains of wavelet-transformed domains can be robust to external attacks such as compression in the case of embedding and extracting watermarks for copyright protection. The high-frequency dependency of pixels in a DC component domain determined as a target domain, in which watermarks are to be embedded, is calculated, in order to embed the watermarks in the target domain in the order of pixels having a higher high-frequency dependency. Accordingly, there is an advantage in that it is possible to minimize a degradation in picture quality caused by the embedding of watermarks in the DC component domain. COPYRIGHT: (C)2003,JPO