Abstract:
Medical Images are widely used around the world today. Especially with new
technology being developed, they are being used for more and more applications in the
medical field. As such, the security of the transfer of medical images is a necessity. Possible
situations might be unauthorized access, tampering of the images and even confusion of a
medical image for a different patient. Usually, image watermarking is used to achieve this.
However, inserting a watermark causes permanent distortions to the image used. For different
applications, these are acceptable for as long as the image is visually comparable to the
original. But for medical images, it is necessary that the image must exactly be the same as
the original, as even small changes could cause a wrong diagnosis and possibly even loss of
human life.
The Reversible Watermarking Application has been built to address these problems.
Reversible Watermarking has the added capability of perfectly restoring the carrier image
used. It allows the user to embed a watermark file to a single or multiple grayscale medical
images. Furthermore, the user can add security by providing a password which is then used
to generate a key for the encryption of the watermarked image using the Advanced
Encryption Standard. The Reversible Watermarking algorithm used, which relies on
Congruence Computations, allows for a high embedding capacity with a relatively small
complexity when compared with other reversible watermarking algorithms. Being the standard
used by the USA, the Advanced Encryption Standard assures that the encrypted image is
secure against possible attacks to gain access to the image.
