A new robust watermarking system based on the DCT domain

The algorithm takes full advantage of local correlation of the host image pixels and the masking characteristics of the human visual system, it chooses DCT blocks by comparing the value of the DCT low frequency coefficients and the amount of the nonzero DCT coefficients of each block. After the embedding process is completed, transforming the DCT coefficients from the frequency domain to the spatial domain produces some rounding errors, because the conversion of real numbers to integers will cause some information loss. The paper uses genetic algorithm to deal with the rounding errors. The experimental results show that, the algorithm can not only make sure the quality of the embedded image and the invisibility of the watermark, but also robust to common image operates, and JPEG compress