A Secure Steganography Method in Low Dynamic Range Images

To improve security, as well as to improve the quality of the stego-image, a steganographic technique by edge adaptive Least Significant Bits (LSB) substitution for Low Dynamic Range (LDR) images is proposed. The smooth and complicated areas of the image are determined by exploiting the dependency of a pixel on their neighborhood. In smooth areas, the method embeds one bit of secret information. In the complicated areas, variable number of bits is embedded. The scheme exploits the neighborhood information to estimate the amount of data to be embedded into an input pixel of cover image without producing perceptible distortions. Also, an optimal pixel adjustment process is used to enhance stego-image visual quality obtained by simple LSB substitution method. The proposed methodology enhances the embedding capacity and improves the stego image quality by adapting Zig-Zag Traversing Scheme (ZZTS). Additionally, modular operation and error correction scheme are also implemented to heighten the image quality and for reliable secret data transfer. The experimental results reveals that the proposed method can achieve higher embedding capacity and better stego-image quality compared with some existing adaptive spatial domain methods. On an average the proposed method can achieve a PSNR value of 42dB.