Abstract: It is studied that the problems in embedding multiple watermarks simultaneously, and proposed an image watermarking scheme which embedded fragile and robust watermarks at the same time. This algorithm, which is based on integer wavelet transform, is public watermarking scheme, both of the two kinds of watermarks can be retrieved without knowing the original image. For retrieving the watermarks, the author proposed a “credible bit” method, which could enhance the robustness of the watermarks. Meanwhile, besides telling you whether an image has been tampered, the fragile watermark could as well, reflect the distortion status in both spatial and frequency domain of the image.

Key words: data hiding, digital watermarking, robust watermarking, fragile watermarking

摘要： 研究了多类数字水印同时嵌入的问题，提出了一种同时嵌入两类水印的图像数字水印算法。此算法基于整形小波变换，两类水印的提取都不需要知道原始图像。还提出了水印的“可信比特”提取的方法，加强了水印的鲁棒性。算法对JPEG压缩、小波压缩、噪声、中值滤波和裁剪有较好的抵抗能力，同时，易损水印除了能鉴别图像是否被篡改外，还能报告图像在空间域和频率域的失真情况。

关键词: 信息隐藏, 数字水印, 鲁棒水印, 易损水印