An image watermarking scheme with hidden signatures

In recent years, digital watermarking has been introduced as a means of effectively protecting copyrights on digitized media such as image, audio and multimedia data. We present a watermarking technique for embedding digital seal images into a digital image, and apply this technique to each spatial and frequency domain of an image. Additionally, this technique does not require the original image to recover the seal image. This not only simplifies the encoding process but also makes up for the weak point which could be shown when an illegal attacker makes proving ownership difficult by creating a fake original. Experimental results show that the proposed watermarking technique is robust to various kinds of attacks.