DWT–SVD–WHTWatermarking Using Varying Strength Factor Derived From Means of the WHT Coefficients

摘要

A hybrid, watermarking technique is presented in this paper. This robust watermarking technique uses discrete wavelet transform (DWT), singular value decomposition (SVD) and Walsh–Hadamard transform (WHT) together in tandem with each other. There are two novelties contained in this paper. First is the combined use of DWT, SVD and WHT, and second is the first ever use of the $$4times 4$$ 4 × 4 block segmentation in the robust watermarking. Another unique feature of the presented technique is that visual quality of the watermarked image has been made controllable. A varying valued strength factor having a different value for every block ( $$8times 8$$ 8 × 8 or $$4times 4$$ 4 × 4 ) of the image has been used. Proposed scheme is very secure as the safety of the embedded watermark is not compromised even if there is an interception of the side information. The proposed technique shows remarkable performance when compared with seven contemporary watermarking schemes.