An improved DCT-based perturbation scheme for high capacity data hiding in H.264/AVC intra frames

Recently, Ma et al. proposed an efficient error propagation-free discrete cosine transform-based (DCT-based) data hiding algorithm that embeds data in H.264/AVC intra frames. In their algorithm, only 46% of the 4 × 4 luma blocks can be used to embed hidden bits. In this paper, we propose an improved error propagation-free DCT-based perturbation scheme that fully exploits the remaining 54% of luma blocks and thereby doubles the data hiding capacity of Ma et al.'s algorithm. Further, in order to preserve the visual quality and increase the embedding capacity of the embedded video sequences, a new set of sifted 4 × 4 luma blocks is considered in the proposed DCT-based perturbation scheme. The results of experiments on twenty-six test video sequences confirm the embedding capacity superiority of the proposed improved algorithm while keeping the similar human visual effect in terms of SSIM (structural similarity) index.