A Blind Image Watermarking Scheme Using Fast Hadamard Transform

摘要

This study presents a Hadamard transform based blind digital watermarking scheme whose extraction process doesn?t require the original image. In this scheme, we use a binary image as the original watermark. During the embedding process, the original cover image is first partitioned into non-overlapped 8x8 blocks and the Arnold transform is performed on the original watermark to make the scheme more robust. Secondly, the Hadamard transform is applied to the blocks. Thirdly, one bit information is embedded in each block by modifying the relationship of two coefficients in the transformed matrix. Finally, the inverse Hadamard transform is performed on the modified coefficient matrix to obtain the watermarked image. The experimental results show that the proposed watermarking method performs well in both security and robustness against general image processing operations and various kinds of attacks, while keeping the invisibility very well.