关键词: Radon投影变换, 感知hash, 修正Hausdorff距离, 认证算法

Abstract: Robustness against geometric distortion is one of the most important problems in image authentication.In this paper，an image watermarking algorithm robust to geometric transformations is proposed，Radon transformation of edge image is used to detect and invert geometric transformations，then a perceptual hash feature detector is proposed to extract significant geometry preserving feature points，finally compare features from two images by developing a modified Hausdorff distance measure.The experimental results show that the algorithm is robust to image processing，such as JPEG compression，common signal processing operations，global as well as geometric transformations，and it is sensitive to content changing manipulations of image data.

Key words: Radon transformation, perceptual hash, modified Hausdorff distance, authentication