Improved Halftone Data Hiding Scheme Using Hilbert Curve Neighborhood Toggling

In this paper, we examine the effects of embedding in randomly selected locations and present a simple but novel high capacity data hiding method for halftone images. Data hiding smart pair toggling (DHSPT) is a flexible method for hiding data directly into halftone images in high embedded capacity applications. It embedded data into randomly selected locations, having the chance of forced single-pixel toggling especially when the payload increases. The proposed method avoids the chance of forced single-pixel toggling by selecting the best pair of connected neighboring pixels out of a sequence of candidate pairs along Hilbert curve for a to-be-embedded bit. The proposed method can significantly improve the visual quality of marked halftone images especially for high-capacity data hiding.