Reversible Watermarking Technique for Medical Images Using Fixed Point Pixel

Quality-sensitive and security concerned applications such as medical images, military images, precious art, law enforcement, and remote sensing do not tolerance slight variation after extraction of watermark. Reversible watermarking has been proposed as a valid solution to enhance security against interception as well as unauthorized modification and to preserve quality of such images. This paper proposes a novel secured reversible watermarking technique for medical images. To enhance high level of security of cover image, the image is partitioned into blocks. The higher correlation is inherent in neighboring pixels. This approach is used to create difference between fixed point pixel and its neighbor pixels in vertical, horizontal and diagonal direction for that block. The difference between neighboring pixels is used as a data embedding space; i.e. global peak of the difference histogram is used to embed watermark. Multiple iterations of the embedding process increase the data hiding capacity. Extraction is done in inverse manner and original image and original watermark can be obtained as a result. Experimental results validate that proposed method achieves better capacity and fidelity as compared to the state of art.