Reversible data hiding in halftone images based on minimizing the visual distortion of pixels flipping

Abstract

With the rapid development of multimedia technology, reversible data hiding (RDH) has been proposed as a technique to protect the hidden information and recover the original image. However, the visual quality of the existing RDH methods in halftone images is not typically satisfactory. In this paper, to reduce the visual distortion, a novel RDH method in halftone images based on minimizing the visual distortion of pixels flipping is proposed. First, based on the human visual system, the suitable marked blocks are selected by the designed visual quality score. Then, by analyzing the block structure of halftone images, the optimal flippable pixels in the suitable marked blocks are selected to embed data. One of the advantages of the proposed method is that the distortion caused by pixels flipping is minimal. The other is that to achieve reversibility, the positions of these optimal flippable pixels can be directly determined by calculating the minimal visual distortion without recording the location map. Experimental results demonstrate that the proposed method ensures high visual quality for marked images and achieves high embedding payload.