Reversible data hiding for medical images using integer-to-integer wavelet transform

Reversible data hiding is a method of hiding secret information (watermark) in some multimedia cover data in such a way that after extracting the watermark, original cover data can be recovered without any loss of information. In this paper, a novel reversible data hiding technique, based on integer-to-integer wavelet transform and histogram-bin-shifting, is proposed for medical images. Images are divided into blocks and smoothness of the blocks is evaluated by calculating entropy of each block. Integer-to-integer wavelet transform is applied over smooth blocks and watermark is embedded in all subbands of detail part. Histogram-bin-shifting technique is used to embed the watermark. The proposed scheme is applied on various medical images and also compared with one of the recent existing reversible data hiding techniques. Higher PSNR values demonstrate the effectiveness of the proposed scheme.