关键词: 离散余弦变换, Arnold 变换, 强度因子, 自适应水印

Abstract: The paper proposes an improved adaptive algorithm based on DCT according to the characteristics of texture，luminance of original image and the feature of human visual system.The algorithm makes pretreatment of watermarking image with Arnold transform，adaptively chooses scaling parameter of embedding and makes a binary watermarking image embedded into the original image，which implements the robustness and invisibility of algorithm.The experimental results show that this algorithm is robust and stable to common digital image processing operations.

Key words: Discrete Cosine Transformation（DCT）, Arnold transform, scaling parameter, adaptive watermarking