| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an electronic watermark detecting device for moving image which can determine electronic watermark data with compressed format, and has a large tolerance, even if it suffers assaults for thinning out a frame from others. <P>SOLUTION: The electronic watermark detecting device classifies a plurality of successive moving image frames into N groups (groups A to N), and embeds watermark data in blocks (A1 to A4), (B1 to B4) to (N1 to N4) at predetermined positions in moving image frames in the respective groups. At this time, the blocks (A1 to A4), (B1 to B4) to (N1 to N4) are extracted from the respective moving image frames, and one DCT coefficient, in which watermark data in each block is embedded, is gathered for each moving image frame to generate a DCT coefficient set äA1, B1 to N1} comprising N DCT coefficients. Then it is decided by majority, whether watermark data is embedded in the DCT coefficient set to decide whether the watermark data is embedded in the DCT coefficient set. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
