A Review on "A Novel Technique for Image Steganography Based on Block-DCT and Huffman Encoding"

This paper reviews the embedding and extraction algorithm proposed by "A. Nag, S. Biswas, D. Sarkar and P. P. Sarkar" on "A Novel Technique for Image Steganography based on Block-DCT and Huffman Encoding" in "International Journal of Computer Science and Information Technology, Volume 2, Number 3, June 2010" [3] and shows that the Extraction of Secret Image is Not Possible for the algorithm proposed in [3]. 8 bit Cover Image of size M x N is divided into non joint 8 x 8 blocks and a two dimensional Discrete Cosine Transformation (2-D DCT) is performed on each of the MN / 64 blocks. Huffman Encoding is performed on an 8 bit Secret Image of size 8 x 8 and each bit of the Huffman Encoded Bit Stream is embedded in the frequency domain by altering the LSB of the DCT coefficients of Cover Image blocks. The Huffman Encoded Bit Stream and Huffman Table are also embedded by altering the LSB of the DCT coefficients of Cover Image blocks as proposed in algorithm [3].