INVISIBLE WATERMARKING OF VOLUME DATA USING WAVELET TRANSFORM

摘要

Protection of copyright for all types of digital data is becoming a very important issue. Watermarking is emerging to be the mechanism of choice for this purpose for image and video data. We believe this is an important issue for volume data as well. In this paper, we propose a method of digital watermarking three-dimensional volume data based on the wavelet transform. The watermark data is embedded into the volume by thresholding and modifying selected coefficients. The algorithm is designed in such a manner that the effect of embedding is invisible in the volume rendering of the watermarked volume. The watermark can be detected using a keyword coded with the threshold values after the wavelet decomposition of the watermarked volume data. Experimental results show the proposed method is imperceptible in the sense that it retains original volume data's rendering quality and at the same time is robust against common attacks such as cropping and adding Gaussian noise.