关键词: 半脆弱水印, 恶意篡改, JPEG压缩, 小波系数, 高频系数

Abstract: Semi-fragile watermarking has attracted much attention because of its important role in multimedia content authentication. In order to distinguish accidental attacks and malicious tampering, semi-fragile watermarks must have the robustness to process general content protection and image manipulation. After JPEG compression, most of the size relationships between the high-frequency coefficients of adjacent wavelets of an image have no changes. According to this fact, this paper proposes a new semi-fragile watermarking algorithm based on DWT transform with tamper localization. The watermark is embedded according to the size relationship between the high-frequency coefficients of the adjacent wavelets of the image. The results of simulation experiments show that the algorithm has large embedded capacity and good anti-JPEG compression performance. At the same time, the positioning for malicious tampering is also very accurate.

Key words: semi-fragile watermarking, malicious tampering, JPEG, wavelet coefficients, high frequency coefficient