Robust and Secured Medical Image Watermarking Using Daub4 and CoAST Transforms

摘要

A hybrid watermarking technique using wavelet and Shearlet transform is proposed in this paper. The DWT variant Daub4 transform model is applied on the medical image to generate different frequency sub-bands. The HL and LH sub-bands which are resistant to compression attacks are chosen for second level of transformation, a DST variant 'Cone adaptive Shearlet transform' technique is used to calculate the Shearlet coefficients of the selected sub-bands. By using SVD on the Shearlet coefficients, the singular values of watermark image are embedded into the singular values of the host image. The proposed approach is examined using three medical images and a watermark image. The experimental results show that the proposed approach is robust against JPEG compression, Geometric and Noise attacks.