关键词: 图像Hash, 奇异值分解, 特征提取, 图像认证

Abstract: A secure and robust image Hash method is proposed based on wavelet transform, pseudo-random block and singular value decomposition. After wavelet transform sub-band is divided into overlapping sub-image blocks, so that the main information of image can be obtained, and the smaller block of tampering with regional information may be obtained by the overlapping block. By pseudo-random dividing and pseudo-random scrambling, Hash cannot be forged without the key, so security of Hash is enhanced. Experimental results show that the proposed method is robust to content-preserving modifications such as JPEG compression, median filtering, additive noise, distortion, re-scaling and the slight geometry transformation, and it is sensitive to different contents and the operation of localized tampering.

Key words: image Hash, Singular Value Decomposition（SVD）, feature extraction, image authentication