Tamper Localization in Wavelet Domain Using Semi- Fragile Watermarking

Abstract- This paper proposes a novel image authentication scheme in the DWT domain. The scheme uses a semi-fragile watermark to detect and precisely locate malicious tampering region in images. The wavelet coefficients selected for embedding are randomly permuted with a secret key, achieving high security. A bit of the watermark is embedded in a group of coefficients by means of quantization. The experimental results show, that our algorithm achieves good image quality and high tampering detection resolution at a low watermark payload, compared to block-based authentication schemes. The watermark is protected against local attacks. We have also conducted experiments to demonstrate the robustness of the watermark against mild to moderate JPEG compression