High Capacity Image Steganography Based on Pixel Value Differencing and Pixel Value Sum

Steganography is the art of hiding information secretly inside a multimedia signal in such a way that its very existence is concealed. In this paper a new image steganography technique has been proposed which is based on the pixel value differencing and the pixel value sum of two consecutive pixels of a cover image. The proposed algorithm hides the secret data in the cover image by manipulating the difference or sum of the non-overlapping blocks of two consecutive pixels. This technique is an improvement over the Wu and Tsai´s PVD technique that is totally based on pixel value differencing. Experimental results validate that the proposed algorithm provides higher capacity than original PVD and produces a stego image having a good visual quality.