A novel edge based image steganography with 2 k correction and Huffman encoding

Image steganography is the art of hiding information into a cover image. It derives from the Greek for covered writing and eventually means ''to hide in the plain sight''. In this paper a novel algorithm which is based on Canny edge detector and 2ˆk correction is proposed. The new method also utilizes Huffman encoding and coherent bit length. Firstly, Canny edge detector is applied to detect the edge of cover image and only edge pixels are selected for embedding payload. Sorting method is used to randomize the edge pixels in order to enhance security. Then Huffman table is constructed. Huffman encoding is practiced to code the secret data before embedded according to Huffman table. Huffman table also should be transmitted to the receiver as secret key. Calculate coherent bit length L on the base of relevant edge pixels and replace with L bits of payload message. Finally, the method of 2ˆk correction is applied to achieve better imperceptibility in stego image. The experiment shows that the proposed method is advantage in PSNR, capacity and universal image quality index (Q) than LSB-3 and Jae-Gil Yu's.