提出一种基于Harr小渡的无损图像水印算法。对RGB图像的B通道进行一维行Harr小渡变换,番取闭环控制,选择嵌入水印后不会发生溢出的像素,自适应地修改其高频子带系数以嵌入水印。实验证明,该算法具有嵌入容量大、透明性好的特性。水印提取无须原始图像,并且可无损恢复原始图像。
Abstract: This paper proposed a lossless digital watermarking algorithm based on Harr wavelet transform, which could recover the original image without any distortion from the marked image after the watermark had been extracted. The selection of wavelet coefficient based on Hart wavelet inverse transformation was to prevent grayscales from possible overflow/underflow of 0-255 that might take place due to the data embedding. This algorithm hided the watermark into coefficients in high frequency sub-band of B color component. Experimental results show that it can embed much more data compared with the existing reversible data hiding techniques. The imperceptibility requirement is satisfied and blind retrieval of the embedded watermark data is also achieved.