Spread spectrum robust watermarking for NURBS surfaces

This paper presents a robust watermarking method for 3D data represented as NURBS. The mark is generated starting from a public message on 64 bits and from a secret information on 22 bits. The mark is embedded into the Discrete Cosine Transform (DCT) coefficients corresponding to the control points, by means of a spread spectrum technique. The detection procedure does not require the original (unmarked) data. The proposed method features transparency and robustness with respect to knot insertion/removal, degree elevation/reduction, geometric attacks, compression, linear and non-linear filtering, noise addition and multiplication. The probability of false alarm is lower than 16.