Digital image watermarking scheme based on quantization index modulation

摘要

Quantization index modulation is a well-known method used for blind watermarking system. In this paper, a novel QIM watermarking scheme is proposed which is based on the difference of neighboring blocks' DCT coefficients. To implement the algorithm, pixels' permutation is performed to the two neighboring blocks to restrict the difference of their corresponding DCT coefficients to a small range. Then, bits of watermark are embedded into the image by modulating the difference to position or negative value. In order to keep the balance between invisibility and robustness, embedding strength is adjusted adaptively for each embedding position according to the texture masking feature of HVS, which improves the performance of the scheme.