Data Hiding Scheme to Improve the Quality of Reconstructed Images for Inverse Halftoning

Abstract

The objective of inverse halftone reconstruction is to convert halftone bilevel images into gray-level images with the minimum distortion, but there is no way to construct a perfect gray-scale image from a given halftone image. A reversible data hiding approach is proposed to improve the recovered image quality for halftone images. The proposed approach firstly computes the difference image between the predicted image using Gaussian filtering from a halftone image and the original gray-scale one. The difference image is then compressed and embedded into the halftone image using a reversible data hiding method. In the image reconstruction process, the marked halftone image is scanned to extract the embedded difference image. Finally, a better quality of reconstructed image will be generated by adding the extracted difference image to the predicted image using Gaussian filtering. Experimental results show that the proposed approach can efficiently improve the quality of reconstructed images for inverse halftoning.