High Capacity Data Hiding for Halftone Image Authentication

Abstract

In an earlier paper [1], we propose a high capacity data hiding scheme for various types of binary images. The scheme ensures that in an M×N image block, the upper bound of the amount of bits that can be embedded is (nlog₂((M×N)/n + 1)( by changing at most n individual pixels. However, changing individual pixels in halftone images will introduce undesirable ‘salt-and-pepper’ noise, or local black or white clusters. In this paper, we propose a new scheme for halftone images which improves [1] in its capability to maintain better quality of the host image after data hiding by changing pixels in pairs rather than individually. The new scheme can still offer a high embedding efficiency. Experimental results show that the new scheme can maintain better image quality.