Stereoscopic shift error expansion reversible watermarking scheme using depth image based rendering

In recent years, reversible watermarking has drawn significant interest from the research community. Watermarking engineering is the practice of embedding a piece of hiding information into a digital medium for several applications including Copyright Protection, Ownership Assertion, and Data Authentication. Reversible watermarking techniques possess the ability to regenerate the embedded message in its entire and without any slightest degradation at the decoding side. The research work presented a novel reversible watermarking technique based on Depth Image Based Rendering (DIBR) for three-dimensional television (3DTV). The proposed technique is inspired by the idea of Difference Expansion (DE). Instead of computing and expanding dv in the same image, the disparity, or the shift error, between the stereoscopic left and right images is used along with the payload as a watermark, which is subsequently embedded in the depthmap of the image. The advantage of doing so is that the depthmap alone can be used in computing the stereoscopic images again. The outcome of the experimental results demonstrates that the proposed technique is reversible with high embedding capacity and imperceptibility. This novel contribution promises ownership protection through the watermark and can generate anaglyph images without the corresponding left and right images. It is also easy to implement in 3DTV DIBR systems for digital display and recording.