关键词: 视觉特征, 离散余弦变换, 自同构, Logistic映射, 图像块序列

Abstract: By using the human vision characteristics，this paper presents an adaptive watermark embedding algorithm based on Discrete Cosine Transform（DCT）.Authors split the original image into sequence of blocks，and then classify them into three sequences：smoothing block sequence，texture block sequence and edge block sequence.According to the classification，the watermark components with different intensity are embedded into different block sequences，so as to enhance the transparency of watermark.Experimental results show that the proposed technique is robust and the quality of the watermarked image is guaranteed．

Key words: visual characteristic, Discrete Cosine Transform（DCT）, automorphisms, Logistic mapping, image block sequence