Geometric Modeling of the Wavelet Coefficients for Image Watermarking

In this paper, a robust image watermarkingmethod based on geometric modeling is presented. Eight samplesof wavelet approximation coefficients on each image block areutilized to construct two line segments in the 2-D space. Wechange the angle formed between these line segments for dataembedding. Geometrical tools are used to solve the tradeoffbetween the transparency and robustness of the watermark data.Due to embedding in the angle between two line segments, theproposed scheme has high robustness against the gain attacks. Inaddition, using the low frequency components of the imageblocks for data embedding, high robustness against noise andcompression attacks has been achieved. Experimental resultsconfirm the validity of the theoretical analyses given in the paperand show the superiority of the proposed method againstcommon attacks, such as Gaussian filtering, median filtering andscaling attacks.

کلیدواژه ها:

image watermarking ، geometric modeling ، wavelet transform