Image Steganography Based on Wavelet Transform and Color Space Approach


This paper presents a color image steganography scheme based on discrete wavelet transform (DWT) and YCbCr color space. The cover image is initially transformed from RGB color space into YCbCr and the Cb component is utilized for hiding a secret grayscale image. Two-level DWT is applied to the selected component to obtain the horizontal sub-band HL2 which is used for the embedding process based on the singular value decomposition (SVD) of the secret image and the obtained sub-band HL2 of the cover image. Structural Similarity Index Measure (SSIM) and Peak Signal to Noise Ratio (PSNR) are measured for evaluating the performance of the proposed scheme. Simulation results show that the proposed steganography method is reliable against several attacks without degrading the visual quality of the cover image. Further, comparative results for the proposed method in YCbCr and RGB color spaces show that the YCbCr space is more efficient in secret image retrieval.