A VQ digital watermark algorithm based oN t-mixture models segmentation

To improve codebook quality in the process of vector quantization, the paper proposes a novel codebook generation algorithm which is based on image segmentation using t-mixture models and greedy EM algorithm. Additionally, in the initial codebook generating procedure, the PNN algorithm is used to reduce LBG algorithmpsilas sensitivity to initial codebook. Experimental results show that the proposed algorithm not only significantly improves codebook quality, but also preserves most details of the original image. An even more important feature is that the proposed algorithm is robust to common image processing operations such as cropping, sharpening and filtering.