Spatial and Transform Domain based Steganography Using Chaotic Maps for Color Images

Abstract

We propose an efficient and robust steganography scheme for color images based on combined spatial and transform domains using chaos theory. The Discrete Wavelet Transform (DWT) domain is used as a transform domain for both secret and cover image to increase imperceptibility and robustness. In order to further improve security chaotic maps are used for scrambling the secret color image before hiding and for selecting randomly the embedding locations in the cover image. After scrambling and embedding the two images are merged in a single image and IDWT is applied to form the stego image. In the extraction process, the secret image can be extracted from the stego image without needing the original cover image. The simulation results of Mean Square Error (MSE), Peak Signal to Noise Ratio (PSNR) and correlation show that the proposed steganography scheme has better invisibility, stronger robustness, higher security and reliability against common image processing attacks, such as filtering and noise attacks, for any kind of image data than pervious approaches. Simulation results show maximum PSNR values of 76.8 dB and correlations of 99.99% for the stego image and of 55.4 dB and 100% for the extracted secret image.