Reversible data hiding scheme for LZW codes using even-odd embedding strategy

This paper proposes a reversible data hiding scheme which embeds the secret data into LZW codes using even odd embedding strategy. It firstly compresses the cover media using LZW algorithm and then constructs a location map of the LZW codes based on their value. The secret data bit stream is converted into base3 representation and then the output LZW codes are used to embed the secret data in two phases. In the first phase, we embed the secret data in the odd valued pixels and in subsequent phase, the secret data digits are embedded into the even valued pixels. The LZW code value is either modified by ±2 or left unchanged for embedding the secret data. Therefore, this scheme is very simple as it basically increases or decreases the pixel value for embedding the secret data. From the experimental results, it is clearly evident that our scheme is able to hide more secret data than the existing state of the art schemes.