DCT-Based Watermarking By Quotient-Embedding Algorithm

A simple watermarking scheme based on the discrete cosine transform (DCT) is proposed. To increase the hidden capacity while maintaining the robustness of the proposed method, the authors use quotient-embedding algorithm to hide the secret message in the selected low-frequency coefficients of a DCT block. Simulations show that the stego-images generated by the proposed method do robustness against image processing operations, such as JPEG2000, JPEG, cropping, processing the negative, quantization, low-pass filtering, noise additions, and so on. Moreover, the PSNR is not bad while the resultant perceived quality and hiding capability are good.