关键词: 图像水印, 几何形变攻击, 特征区域, 纹理方向, DCT量化

Abstract: This paper proposes a image watermarking scheme efficiently robust to basic geometrical attacks such as rotation，translation and scaling.In the embedding scheme，a geometrical invariable is proposed，which is based on the invariability of statistical feature in the circular image area.Using this invariability，the geometrical distortion is first retrieved.In embedded scheme，the 2 bits watermarking information is embeded in one embedding point.Using HVS，watermarking can be embeded adaptively in the texture direction of visual insensitive area.In extract scheme，feature circular area is used to remedy distortions，and then watermarking is extracted blindly in the DCT domain.Experimental results suggest，the watermarking scheme has the better transparency，at the same time，it has the strong ability in resisting basic geometrical distortions，also it has the better robustness for common image processing，JPEG compression and etc.

Key words: image watermarking, geometrical distorted attack, feature area, texture direction, DCT quantization