Applying 3D Polygonal Mesh Watermarking for Transmission Security Protection through Sensor Networks

Figure 6

An example of solving the causality problem. (a) After the watermarking process, 𝑃₀, 𝑃₁, and 𝑃₂ have been modified to 𝑃^′₀, 𝑃^′₁, and 𝑃^′₂. In this situation, the prongness value of 𝑃₀ increases, so other vertices may substitute 𝑃₀ to be a new local minimum. (b) 𝑃^′₀ can be slightly moved along its norm direction to 𝑃^′′₀, so that its prongness value can be decreased and local minimum again obtained.

(a)

(b)