Watermarking of Space Curves using Wavelet Decompostion

This paper describes an imperceptible, non-blind, fragile watermarking technique for space curves. The proposed technique employs a wavelet-based approach, and computes a multi-resolution representation of the space curve to embed a watermark so that it has widespread presence in the curve. Watermarks that are widely spread within the host data cannot be easily damaged by cropping and replacement attacks that result in localized alteration of the host data. A variety of wavelet families are exploited and experimental results provide a comparison of the performance of different wavelets in terms of the watermark’s imperceptibility and tolerance to attacks. To quantify space curve distortion, a signal-to-noise ratio is used, and a linear correlation measure is employed to determine the resistance of the watermark to modifications. Results indicate that watermark insertion using wavelet packet decomposition outperforms orthogonal wavelet decomposition in terms of imperceptibility and diversified presence of the embedded watermark.