| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To insert an electronic watermark into an image without degrading image quality for the setting of a method for embedding the electronic watermark, and to enhance its detection efficiency. <P>SOLUTION: The method for inserting electronic watermark data which insert the electronic watermark data having proper strength to each picture type comprises steps for: taking out a block of k×k pixels from the image; performing the DCT (discrete cosine transform) of the block; quantizing a coefficient of the DCT after DCT transform; deciding the picture type; selecting one kind of the electronic watermark data according to the picture type from an electronic watermark data table in which j kinds of electronic watermark data are stored from first electronic watermark data to j-th electronic watermark data for each picture type; and inserting the selected electronic watermark data into the data after the DCT transform. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
