关键词: 数字水印, 能量分析, 向量相似度, 峰值信噪比, 水印提取正确率

Abstract: The analysis of energy helps to balance the imperceptibility and robustness of digital watermarking. Currently, the digital watermarking embedding energy is often determined by repeat testing. Firstly, this paper introduces the watermarking model which is based on the similarity of vectors, and then it quantificationally analyzes the impact of embedding strength and the secret key on the Peak Signal to Noise Ratio（PSNR） and watermarking correct extraction rate. Finally, simulation experiments show that with the embedding strength increasing, the impact of the secret key on the PSNR and watermarking correct extraction rate is reduced; for a particular embedding strength, there are optimal subsets of the secret key which make watermarking correct extraction rate maximum. It is significant for the design of digital watermarking which is based on the similarity of vectors, and it can calculate the energy which is required to embed in watermarking in theory.

Key words: digital watermarking, energy analysis, similarity of vectors, Peak Signal to Noise Ratio（PSNR）, watermarking extraction accuracy