An adaptive reversible information hiding method based on search-order coding for VQ-compressed images

Abstract

In the last decade, a common information hiding technique applied to lossy compressed images embeds secret data by adjusting the indices formed by the vector quantization (VQ) scheme. After extracting embedded data, this method cannot recover the original VQ-compressed codes. This method is called the irreversible information hiding method. On the contrary, the technique which is able to recover the original VQ-compressed codes after extracting of the embedded data is called the reversible information hiding method. There is little research related to reversible information hiding methods for the VQ-compressed images. In this paper, we propose a simple and adaptive reversible information hiding method applied to a VQ-compressed image. In our method, the VQ-compressed image is further compressed using the search-order coding algorithm. It simultaneously embeds the data bits into the indices. Our method embeds any length of data bits into the VQ-compressed image. The experiment results show our method outperforms other methods in embedding capacity and compression ratio.