AN IMAGE WATERMARKING SCHEME BASED ON WAVELET AND MULTIPLE-PARAMETER FRACTIONAL FOURIER TRANSFORMS

摘要

We propose an improved digital image watermarking technique using multiple parameter discrete fractional Fourier (MPDFRF) and discrete wavelet (DW) transforms. The original cover image is decomposed into four wavelet sub-bands using the DW transform, followed by a segmentation of each sub-band into blocks. Then the MPDFRF transform is applied to each block, and the watermark is embedded into each transformed block. Several experiments are conducted to compare the robustness of the proposed method with the discrete fractional Fourier (DFRF) transform. The experimental results demonstrate better visual imperceptibility and an improved resiliency against several attacks.