ブロックの分散・平均値を用いた画像電子透かし

Abstract

This paper presents a watermarking algorithm using statistics of image blocks such as their pixel value variances and averages, and demonstrates its performance via simulation experiment results. This algorithm utilizes human vision characteristics such that subjective image quality degradation is little in edge and texture portions, and embeds watermark information in a way that blocks with higher variance have priorities for their watermark information embedding. Furthermore, in the algorithm, pixel values are quantized beforehand by selecting an appropriate number of blocks in order to enhance its robustness against attacks trying to erase the watermarked information. The simulation experiment results show that the algorithm can enhance its robustness against quantization attacks while suppress image quality degradation.