Robust Image Watermarking Method using Wavelet Transform

Abstract

In this paper a robust watermarking method operating in the wavelet domain for grayscale digital images is developed. The method first computes the differences between the watermark and the HH1 sub-band of the cover image values and then embed these differences in one of the frequency sub-bands. The results show that embedding the watermark in the LH1 sub-band gave the best results. The results were evaluated using the RMSE and the PSNR of both the original and the watermarked image. Although the watermark was recovered perfectly in the ideal case, the addition of Gaussian noise, or compression of the image using JPEG with quality less than 100 destroys the embedded watermark. Different experiments were carried out to test the performance of the proposed method and good results were obtained.