说明：  在对图像数字水印和图像压缩技术进行深入研究的同时，提 出了在图像压缩域内同时嵌入一个鲁棒水印和一个脆弱水印的双水 印方案
(esides researching on the image digital watermarking and image compression technology in—depth，the thesis has put forward a method to embed a robust and af ragile watermark in the compression domain of the image．)