Robust watermarking on the joint spatial-spectral domain [image watermarking]

With the advance of the Internet, the transmission, distribution and access to digital data have become easier than before. This advance brings with it the challenge of protecting the content of digital data. This problem has generated the need for research in digital watermarking. Traditionally, the problem of digital image watermarking has been approached in the spatial and spectral domains. In this paper, a new approach that combines the two domains through a joint time-frequency representation is considered. This new approach provides flexibility in determining the pixels to be watermarked and increases the data hiding capacity. An easy to implement watermark embedding algorithm and the corresponding detection algorithm are presented. The watermarking algorithm is tested under different attacks and is shown to be robust.