Reversible data hiding scheme based on the AMBTC compression technique and Huffman coding

Abstract

This paper proposes a reversible data hiding (RDH) method based on the absolute moment block truncation coding (AMBTC) compression technique and Huffman coding. First, AMBTC is used to compress the original greyscale image to obtain two quantisation levels and a bitmap of each block. Next, the bitmap of each block is converted into a decimal number to calculate the frequency of the decimal number. A user-defined threshold is used to classify the block as embeddable or not. If the frequency of the decimal number is larger than or equal to the threshold, the bitmap is embeddable and is then compressed by the Huffman coding technology. The scheme takes the redundancy of each block by using the Huffman code instead of the bitmap to embed secret information. Experimental results show that our proposed scheme has a better hiding payload than other methods, as well as an acceptable image visual quality.