A Triple-Bit Coding Scheme for Digital Image Watermarking

With the wide use of the internet and digital images, watermarking became very popular and brought the attention of many researchers. Image watermarking is the process of adding additional information (e.g. text) to the original image in order to provide copyright protection. Various ways of watermarking in both the transform domain and the spatial domain have been proposed. Watermarking algorithms aim to improve the watermark robustness, and to provide high imperceptibility and security. The impact of channel coding on the performance of watermarking is effective. It appears natural if one compares the watermarking problem with the transmission of a signal over a noisy channel. In this paper, a triple-bit error-correcting algorithm for digital image watermarking in the transform domain is proposed. The algorithm considers the stego-image as a channel and the compression attack as a noise signal. The proposed algorithm was evaluated against two well-known techniques, which are the Block coding and the Convolutional error-correcting code; it showed very good results in terms of watermark robustness comparing to the other two techniques. The proposed algorithm has been implemented using MATLAB.