A robust 3-SWT multiple image steganography and contrast enhancement technique

Abstract

Steganography is used to hide data in form of invisible communication. It is used to provide secret communication between two parties. In this research we divide work into two phases-(i) first phase-apply image steganography with 3-stationary wavelet transform over multiple color images. In second phase increase level of work by applying contrast enhancement with 3-level stationary wavelet transform. Firstly, we take four pictures: one is cover image (CI) and another is secret image (SI). In the process of embedding, we divide RGB image into three planes: Red, Green and Blue. In the first phase, embed multiple color secret images into a single cover image for providing security. In the second phase, before 3-SWT decomposition, apply contrast enhancement on cover image and all secret images. We evaluate performance on the basis of peak signal noise ratio (PSNR) and structural similarity matrix (SSIM) with different varying weights. This algorithm is compared with 1-discrete wavelet transform (DWT) and first phase of proposed system. In the extraction process, recover three secret images from stego image. In this analysis, improved PSNR value as compared to previous paper. The experimental outcomes of PSNR will be reached upto 66.95%. The advantage of SWT is time-invariant transform as compared to DWT. The main work of SWT is improving smoothness of an image and enhance the image for image quality.