| 摘要 |
PROBLEM TO BE SOLVED: To pad watermark information having a high resistance to an attack, without damaging the image quality at the time of padding image data with an electronic watermark. SOLUTION: Input multi-level image data are subjected to wavelet conversion to output a coefficient, and this coefficient is processed in an electronic watermark padding device 103, and information for extracting a composite image padded with watermark information and watermark information is subjected to inverse wavelet conversion processing and is outputted. When watermark information is padded in a wavelet conversion area, a stronger electronic watermark is padded for a coefficient having a large absolute value out of coefficients included in sub-bands other than the lowest area sub-band. |
