Embedding of a watermark signal is an interesting research and application field in the
copyright protection of multimedia signals (images, sounds, movies)[1–4]. The goal is to
embed the watermark that is imperceptible in the image, while the copyright holder can
detect its existence, by using proper private information—key. Commonly used methods are
based on embedding watermark signals in the space or spatial-frequency domain [1].
Recently, watermarking in the combined space/spatial-frequency domain has been defined …