DCT based reversible watermarking technique for Medical Images with improved quality of watermarked image

Abstract

These days, it is extremely easy to duplicate and distribute digital media, and because of this the protection of intellectual property is a very important issue. In case of medical images, the patient’s information and details can be securely hidden in the cover image. But being a special case the used data hiding technique should be properly selected. Being Medical Images it is necessary to retrieve the exact medical image after removal of the watermark. In this paper a simple reversible watermarking technique based on DCT is implemented. After embedding watermark, it is necessary to maintain quality of the medical image. To improve the quality of the watermarked medical image, the blocks in which the watermark is embedded, is selected based on variance of the blocks. The algorithm is tested for various medical image modalities. Being a simple algorithm it is fast and efficient.