Histogram Shifting Lossless Data Hiding Based on Space Filling Curves

A lossless data hiding scheme, which can restore the original image completely after data extraction, is presented in this paper. In the proposed method, a cover image is reordered into a sequence using space filling curves. For each pixel (except the first pixel) in the sequence, a pixel difference is generated between the pixel and its neighbor pixel. Due to the inherent structure of images causes a correlation of adjacent pixels, by utilizing the space filling curve scanning we can improve the embedding capacity while keeping the distortion low. Unlike most of the currently available lossless data hiding approaches, in which the visual quality of the stegoimage will be drastically degraded if the multi-layer embedding is applied, the proposed scheme can apply the multi-layer embedding to the cover image conveniently. Experimental results show that the proposed algorithm provides high embedding capacity while keeping the distortions low.