Integer wavelet transform based watermarking scheme for medical image authentication.

In this work, a blind watermarking scheme has been proposed for medical image authentication. The scheme can embed patients' records in digital format into a digital copy of a computerized scan. In this scheme, an Integer Wavelet Transform (IWT) is applied to the medical image prior to the embedding procedure. Here LH, HH, and HL sub-bands of the IWT are used for watermark embedding. To ensure the security of the scheme a SHA-512 hash algorithm is applied to the watermark, and the hash value is embedded within the digital copy of the scanned image to ensure the authenticity of the scanned copy. Depending on a shared secret key, the IWT coefficients are selected from random positions before embedding the watermark. The results show that the proposed scheme achieved 78.5 dB PSNR with an NCC value of 0.9805, and SSIM is near about 1 after embedding 65,280 bits of watermark information. The experimental outcomes are compared with some state-of-the-art schemes to show the superiority of the proposed scheme in terms of robustness and imperceptibility. [ABSTRACT FROM AUTHOR]