A Lossless Data Hiding Method by Histogram Shifting Based on an Adaptive Block Division Scheme

A lossless data hiding method based on histogram shifting is proposed, which employs a scheme of adaptive division of cover images into blocks to yield large data hiding capacities as well as high stego-image qualities. The method is shown to break a bottleneck of data-hiding-rate increasing at the image block size of 8 × 8, which is found in existing histogram-shifting methods. Four ways of block divisions are designed, and the one which provides the largest data hiding capacity is selected adaptively. A series of experiments have been conducted, and superiority of the proposed method is shown by comparing the experimental results with those of other histogram-shifting based methods. A good property of the proposed method observed in the experiment is that data hiding rates are increased without degrading the stegoimage quality expressed by the peak signal-to-noise ratio measure.