Data Hiding Scheme Using Covering Codes in Halftone Images Based on Error Diffusion

This paper proposes a new data hiding scheme based on covering code in process of producing halftone images. The scheme is mainly to do error diffusion in gray-level images beforehand, and produce the fixed length sequence of the halftoning binary code according to the rule of covering code. Then, after embedding secret data in the binary code, the gray-level images renew to do the error diffusion by the new binary code. While all pixels of gray-level image have been processed, not only can achieve to render gray-level images to halftone images, but can embed secret data into halftone images. The experimental results prove the quality of stego-halftone image of our scheme better than the scheme that the secret data directly embed to halftone images using covering code. Moreover, the average of PSNR in our proposed scheme only degrades 4.77 dB between the stego-halftone image and original halftone image, and data hiding capacity can hold 42%.