Wavelet Based Image Authentication and Recovery

In this paper, we propose a secure semi-fragile watermarking techniquebased on integer wavelet transform with a choice of two watermarks tobe embedded. A self-recovering algorithm is employed, that hides theimage digest into some wavelet subbands for detecting possible illicitobject manipulation undergone in the image. The semi-fragility makesthe scheme tolerant against JPEG lossy compression with the qualityfactor as low as 70\%, and locates the tampered area accurately. Inaddition, the system ensures more security because the embeddedwatermarks are protected with private keys. The computationalcomplexity is reduced by using parameterized integer wavelet transform.Experimental results show that the proposed scheme guarantees safety ofa watermark, recovery of image and localization of tampered area.