Automatic contrast enhancement with reversible data hiding using bi-histogram shifting

Abstract

Aiming at resolving artificial distortions in marked images and increasing embedding capacity, this paper presents an automatic contrast enhancement (CE) method with reversible data hiding (RDH) using bi-histogram shifting (BHS). Current CE methods introduce distortions in marked images as embedding capacity increases. This paper focuses on resolving these artificial distortions by achieving better CE and increasing embedding capacity in marked images. The proposed method adaptively selects two peak bins and two lower bins based on four conditions depending on image brightness using the brightness preservation (BP) method. The two peak bins are used as splitting and embedding bins, whereas the lower bins are used as combining bins. The proposed method pairs each peak bin with a lower bin and performs BHS in the opposite direction to achieve histogram equalization (HE) while embedding secret data in marked images. The proposed method is compared with existing methods and evaluated with PSNR, SSIM, RCE, REE, RMBE, and VIF quality assessment metrics. Experimental results show that the proposed method's marked images are visually and qualitatively superior to existing works, with an average increase in embedding capacity of 37.6%. The proposed method is reversible and performs the extraction of embedded data to retrieve the original images losslessly.