A Novel Image Watermarking Algorithm with Fast Processing Speed

A novel robust image watermarking algorithm based on block Hadamard transform (HT) is proposed in this paper. The watermark image is displaced to destroy space relativity and expanded to get watermark binary sequence. The original image is subdivided to 8 x 8 blocks and executed HT transform, then middle frequency HT coefficients are selected to hide watermark. The correlation of watermark code and the subtraction of HT coefficients between embedded and original image is used to determine each bit when detecting watermark. The contrast experiments between our scheme and similar algorithm based on other transform domain show that the robustness of our scheme is comparable while the processing speed is much more faster.