针对现有基于频域的无损数字水印算法在实施可逆性和嵌入容量上的不足,提出一种基于整数小波变换的无损数字图像水印算法,用于图像的大容量可逆信息隐藏。首先对图像进行LeGall5/3整数小波变换,然后在高频子带中采用直方图平移方法嵌入水印。为了获取最大的嵌入容量和减少图像的失真,分别提出嵌入参数和停止参数选择方法。同时,为了防止溢出现象和减少附加信息,提出新的产生位置映射图方法。实验结果证明了该算法在水印图像的保真度和嵌入容量上面具有较好性能。另外,与相似算法的比较证明了该算法的优越性。该算法适合于数字图像载体中实施隐秘通信。
In order to overcome the deficiencies of execution reversibility and embedding capacity in frequent domain-based lossless digital watermarking algorism,we presented an integer wavelet transform-based lossless digital image watermarking algorithm for image's reversible data hiding with high capacity. First we conducted the LeGall5/3 integer wavelet transform on original image,and then embedded watermark into high frequency sub-bands using histogram shifting method. In order to obtain the maximum embedding capacity and to reduce image distortion,we proposed the embedding parameters and stopping parameters selection method respectively. At the same time,in order to prevent overflow phenomenon and to reduce additional information,we proposed a new location mapping generation method. Experimental results showed that the proposed algorithm had good performances in fidelity of watermarked image and embedding capacity. In addition,the comparison with similar method also proved the superiority of the proposed algorithm. The algorithm is applicable to carrying out secret communication in digital image carries.