Reversible Steganography Based on Side Match and Hit Pattern for VQ-Compressed Images

Data hiding is a technique which embeds secret data into cover media. It is important to the multimedia security and has been widely studied. Recently, some researchers paid attention to reversible data hiding methods. These methods can reconstruct the original image from the stego-image when embedded data are extracted. In this paper, we propose a new reversible steganographic method for vector quantization (VQ) compressed images. The new method uses the hit pattern to achieve reversibility, and the hit pattern strategy successfully reduces the overhead. The codebook is partitioned by the extension method which makes the stego-image have good visual features. Also, a look-up table is used to speed up the partitioning operation. Compared to Chang et al.´s method, the experimental results show that the proposed method has higher capacity, better visual quality, and lower running time.