A new oblivious watermarking method using maximum wavelet coefficient modulation

In this work, a new robust oblivious image watermarking scheme based on local maximum wavelet coefficient modulation for copyright protection is presented. The original unmarked image is not required for watermark extraction. Wavelet coefficients are grouped into different blocks and one watermark bit is embedded in each block. LH sub band (third level) of a Discrete Wavelet Transform (DWT) of a host image is selected for embedding a watermark. This scheme demonstrates robustness to some common signal processing attacks such as average filtering, JPEG compression and additive Gaussian noise. Experimental results show that there is a significant improvement with the proposed algorithm over the existing schemes in terms of Normalized Correlation Coefficient (NCC) and Peak Signal to Noise Ratio (PSNR)