Nested Quantization Index Modulation for Reversible Watermarking and Its Application to Healthcare Information Management Systems
Figure 6
(a) The simplest nested QIM with two blocks (: the host image, : the intermediate watermarked image, : the final watermarked image, and : the watermarks, and : the secret keys, and : the quantization steps, and : the quantization errors, and : the normalized quantization errors). (b) The block used in the nested QIM.
