A secure dual digital watermarking technique based on wavelet transform and chaos system

Abstract

To guarantee copyright protection and integrity authentication simultaneously, this paper proposed a dual digital watermarking scheme: Transform the image by a two-stage wavelet transform, embed a robust watermark in the low frequency sub image and embed a fragile watermark in the high frequency sub images. A logistic chaos algorithm and a Arnold transform were used to add to the difficulty of breaking, leading to the failure of fragile watermark extraction from tampered image. The algorithm can extract a robust watermark, even though the stego image is badly damaged. It can prove a very feeble modification to the image by a fragile watermark. Theoretical analysis and experimental results show that this technique is an integrated and secure scheme for multimedia production protection.

An Improved QIM Watermarking Algorithm

“…The extraction process of IQIM Quantization is reverse process of watermark embedding process:(1) Converts the embedded watermark image into YCbCr space, separate the Y, Cb, Cr three component of image. (2) In regard to Cb, Cr high frequency coefficients of the watermark, using the inverse method of section2.2 step 3 and 4 to extract watermarking. (3) In regard to the component of Y low frequency coefficients of the watermark, using reverse formula 2 to extract low frequency watermark.…”