A Novel Discrete Fractional Complex Hadamard Transform for Medical Image Encryption

This paper introduces a new discrete fractional complex Hadamard transform (FCHT) and its generalized form, the multiple-parameter FCHT (MFCHT). The MFCHT is applied to the medical image encryption. Both subjective observations and objective evaluations are conducted to validate the effectiveness of the proposed algorithm, and the simulation results demonstrate that the proposed MFCHT outperforms previous transform-based algorithms, including the discrete fractional Fourier transform and the discrete fractional Hadamard transform, in terms of robust image preservation against blind attacks in the medical image encryption.