Imperceptibility Improvement of Dual Image Steganography using Kekre’s LUV and CIE-LAB Color Spaces

Abstract

This paper puts forth the improvement in imperceptibility of dual steganography method earlier implemented using YCbCr color space by proposing the use of Kekre’s LUC color space and CIE LAB color space. The dual steganography having combination of frequency domain and spatial domain enables the embedding of two secrets in one cover image by means of the discrete wavelet transform (DWT) based and least significant bit (LSB) based steganography methods. The dual steganography increases he payload which is embedded in a cover image. The first secret image embedded by using DWT in Kekre’s LUV, CIE-LAB, and YCbCr color space models to obtain intermediate Stego image. The second secret image is embedded into red, blue and green channels of color intermediate Stego image using LSB to get final Stego image. The experimentation is done using 20 cover images and two secret message images. For assessment of imperceptibility of the steganography method four image quality assessment metrics are deployed as mean squared error (MSE), structural similarity (SSIM), correlation coefficients (CC) and peak signal to noise ratio (PSNR).Overall empirical analysis shows that the proposed use of color space CIE-LAB and Kekre’s LUV gives superior imperceptibility than existing suggested use of YCbCr color space for all concentration values of the secret image. In fact, the effect of concentration level of secret image embedding is negligible on the result in case of proposed use of CIE-LAB and Kekre’s LUV color spaces. The proposed use of color spaces is also tested against various attacks and it is found that the Kekre’s LUV color space is as robust as YCbCr color space under all attacks. The advantage of kekre’s LUC color space is lighter conversion complexity for inter-conversion from RGB color space. Thus, the proposed use of Kekre’s LUV and CIE LAB color space givers better performance in dual mage steganography with increased payload as compared to YCbCr color space.