Comparative Analysis of Different Transformation Techniques in Image Steganography

Abstract

Image steganography is a way of transferring confidential messages through a cover image which can’t be observed by a third party. In this paper we have a comparative study among image steganography using LSB technique and Huffman encoding with DCT and DWT. In first case, the image is 8x8 blocks processed and 2D-DCT applied on it and Huffman encoding is applied on the text message. Then, the Huffman encoded binary string is inserted in the cover image. Then 2D-IDCT is applied on that inserted image. In second case, 2D-DWT is applied on the cover image and Huffman encoding is applied on the text message. Then, the Huffman encoded binary string is inserted in the cover image. Then, 2D-IDWT is applied on the inserted image. After applying IDCT and IDWT the images found are stego images. The PSNR value of these two stage images are compared and found that DWT stage image has better PSNR value.