Auxiliary Metadata Delivery in View Synthesis Using Depth No Synthesis Error Model

In this paper, a novel data hiding scheme, 3D unseen visible watermarking (UVW) based on a depth no-synthesis-error (D-NOSE) model is proposed. The proposed method has the ability to detect and discover which region of a depth image is suitable for watermark embedding and calculate optimal variance in pixel values for watermarking. The watermark is embedded into the suitable region by modifying the depth map with optimal variation pixel values to ensure that the watermarked cover can be perceived the same as the original one with no synthesis error under normal rendering conditions. In the proposed UVW scheme, hidden information can be extracted successfully by the human visual system (HVS) when changing the rendering conditions. Experimental results prove that the proposed scheme has strong robustness and imperceptibility while depth distortions follow the thresholds derived from D-NOSE model. Practical applications and limitations of the proposed 3D UVW for auxiliary information delivery are also discussed in this paper.