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.