Depth-image-based rendering (DIBR) is a method to represent a stereoscopic content. The DIBR consists of a
monoscopic center view and an associated per-pixel depth map. Using these two components and given depth
condition from a user, the DIBR renders left and right views. The advantages of DIBR are numerous. The user
can choose not only the monoscopic or stereoscopic view selectively, but also the depth condition what he prefers
when he watches a stereoscopic content. However, in the view of copyright protection, since not only the center
view but also each left or right view can be used as a monoscopic content when they are illegally distributed,
the watermark signal which is embedded in the center view must have an ability to protect the respective three
views. In this study, we solve this problem by exploiting the horizontal noise mean shifting (HNMS) technique.
We exploit the fact that the objects in the view are shifted only to horizontal way when the center view renders
to the left and right views. Using this fact, the proposed stereoscopic watermarking scheme moves the mean of
horizontal noise histogram which is invariant to horizontal shifting, and we achieve good performance as shown
in the experimental results.