NSCT-based robust image watermarking in DC components of APDCBT using singular value decomposition

Abstract

Digital watermarking is an emerging solution for securing multimedia products from illegal or unauthorized manipulation. Robustness and visual imperceptibility are two characteristics of watermarking, which can be achieved by utilizing various transform techniques. Our proposed robust watermarking technique used a hybrid transform composed of three transform techniques: nonsubsampled contourlet transform (NSCT), all phase discrete cosine biorthogonal transform (APDCBT), and singular value decomposition (SVD). NSCT has outstanding shift-invariant, and directional properties; its low-frequency band of an image contains a large amount of visual information. Besides, APDCBT can attenuate the high-frequency components, and its direct current (DC) components have more visual details of an image. For gathering these DC components, we applied APDCBT on the low-frequency band of NSCT of a cover image after 8 × 8 block portioning. Then the binary watermark is inserted into perceptually significant DC components using SVD. The feasibility of the proposed technique is justified using computer simulation as well as this scheme is passed through imperceptibility and robustness test. Finally, a comparative analysis demonstrates that our proposed method achieves satisfactory improvements over the existing two watermarking techniques.