Efficient Reversible Watermarking Technique with Contrast Enhancement for Color Images

In this paper histogram bin shifting based reversible data hiding algorithm for color images has been proposed. In this technique binary bits are embedded directly by addition and subtraction in two highest bin chosen and this process is repeated in modified histogram. A location map is generated by pre -processing to prevent the unnecessary overflow and underflow. All other pixels except two highest bins are also manipulated for contrast enhancement. Embedding of binary secret data is done on the each color component (Red, Green, and Blue) of color images. Secret Binary data bits are embedded in random permutation manner to secure the data from unauthorized receiver. Extraction of embedded binary bits is done by inverse algorithm of embedding process and original image is recovered by reverse manipulation embedding process. This proposed algorithm provide high embedding capacity with low distortion of original quality of image which may be used in different medical, military and satellite application. KeywordsReversible Watermarking, Visual Quality, Contrast, PSNR. ________________________________________________*****___________________________________________________