An Efficient Image Watermarking Scheme Using BFS Technique Based on Hadamard Transform

Digital watermarking is a modern technology evolved to prevent illegal copy or reproduction of digital content. In recent years, several digital watermarking techniques have been presented based on discrete cosine transform, discrete wavelet transform and discrete Fourier transform. In this paper, we propose a robust and efficient digital image watermarking algorithm based on Hadamard transform. This algorithm can embed or hide an entire image or pattern, such as a company’s logo or trademark, as a watermark directly into original image for copyright protection. In proposed scheme, a best-first search technique is used to find the longest increasing sequence in each block of an image in which to embed the watermark. The experimental results show that the proposed algorithm offers better image quality and more robustness under various alterations, such as JPEG compression, cropping, sharpening and filtering among others. The results have proved the higher imperceptibility and robustness of this scheme when compared with other available watermarking techniques.