A watermarking model for omni-directional digital images

In this contribution, a watermarking system for omni-directional images is presented. To cope with the peculiarities of this media, an ad-hoc watermarking technique has been designed. In particular, since the users can only view a small portion of the 360° images, the viewport, the watermarking procedure has been designed for allowing the extraction of the watermark even from a single viewport. In this way it is possible to protect the ownership of the content even if only a viewport is illegally distributed. The experimental results show that the proposed system is robust against several kinds of attacks, outperforming the current state-of-the-art in omni-directional image watermarking.