Customer Authentication of Digital Imaging Using Hybrid Watermarking

In this paper, we present a robust and imperceptible hybrid watermarking method in order to be applied to digital color images with the purpose of detecting illegal copies, using a customer robust authentication. In order to improve the robustness of the proposed method against several common signal processing and geometrical attacks, two different algorithms for embedding a unique watermark are used. The watermark is composed by a binary pattern obtained from a cryptographic hash of the customer data. Discrete Fourier Transform (DFT) and a bi-dimensional histogram, both into the YCbCr color model domain, are used to embed the watermark bit sequence. The quality of the watermarked image is measured using the following well-known indices peak signal to noise ratio (PSNR), mean square error (MSE) and structural similarity index (SSIM). Experimental results show the robustness of the proposed method preserving at the same time a high quality on the host image.