Blind image watermarking technique based on differential embedding in DWT and DCT domains

Ali Benoraira,Noureddine Boucenna,Khier Benmahammed

doi:10.1186/s13634-015-0239-5

Ali Benoraira, Noureddine Boucenna + Show 1 more

Open Access

https://doi.org/10.1186/s13634-015-0239-5

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Abstract

This paper presents a new blind and robust image watermarking scheme based on discrete wavelet transform (DWT) and discrete cosine transform (DCT). Two DCT-transformed sub-vectors are used to embed the bits of the watermark sequence in a differential manner. The original sub-vectors are obtained by the sub-sampling of the approximation coefficients of the DWT transform of the host image. During the extraction stage, the simple difference between the corresponding sub-vectors of the watermarked image, gives directly the embedded watermark sequence. Experimental results demonstrate that the proposed technique successfully fulfills the requirement of imperceptibility and provides high robustness against a number of image-processing attacks, such as JPEG compression, noise adding, low-pass filtering, sharpening, and bit-plane removal. Our scheme exhibits also an acceptable to good performance against some geometrical attacks such as resizing and cropping.

Highlights

The process of embedding a watermark in a multimedia object is termed as digital watermarking
To further emphasize the efficiency of combining discrete wavelet transform (DWT) and discrete cosine transform (DCT) domains, we propose a reduced DCTbased version of our method which is based on the DCT domain only
3 The DCT-only method To justify the utility of combining DWT and DCT domains, we propose here a reduced version of our method based only on the DCT domain

Summary

Introduction

The process of embedding a watermark in a multimedia (image, audio, or video) object is termed as digital watermarking. Zhao et al proposed a watermarking approach implemented as a DCT-DWT dual domain algorithm and applied for the protection and compression of cultural heritage imagery [10] They employed Haar DWT domain to embed the watermark in the components of the image that are of perceptual significance. The watermark bits are embedded in the singular values’ vector of blocks within low frequency sub-band in host image hybrid DWT-DCT domain. After scrambling the binary watermark, a block-based DCT transform of the first-level DWT LL sub-band is computed and two PN-sequences of the watermark bits are embedded in the mid frequency coefficients of the corresponding DCT blocks.

Proposed method

The extraction process

Findings

Conclusions