  Reversible image watermarking guaranties restoration of both original cover
and watermark logo from the watermarked image. Capacity and distortion of the
image under reversible watermarking are two important parameters. In this study
a reversible watermarking is investigated with focusing on increasing the
embedding capacity and reducing the distortion in medical images. Integer
wavelet transform is used for embedding where in each iteration, one watermark
bit is embedded in one transform coefficient. We devise a novel approach that
when a coefficient is modified in an iteration, the produced distortion is
compensated in the next iteration. This distortion compensation method would
result in low distortion rate. The proposed method is tested on four types of
medical images including MRI of brain, cardiac MRI, MRI of breast, and
intestinal polyp images. Using a one-level wavelet transform, maximum capacity
of 1.5 BPP is obtained. Experimental results demonstrate that the proposed
method is superior to the state-of-the-art works in terms of capacity and
distortion.
