Abstract :
Hybrid image watermarking technique is proposed in this paper which takes the advantages of different transforms like RDWT, DCT, SVD and trigonometric functions. So, all the functions are combined at one place to create a non-blind, robust and reversible watermarking scheme. The algorithm is verified on different format host images and different intensity watermarks. To measure the effectiveness of the method, the correlation based extraction mechanism is used with the tolerance level of 0.8 for robustness. And PSNR is measured to check fidelity of watermarked and extracted original image. The experimental results show that the algorithm is robust against many attacks like rotation, scaling, blurring, contrast, JPEG Compression, histogram equalization, affine transformation, mean filtering, Gaussian noise. NCC remains above tolerance level even when the image is completely distorted and also the visual quality of extracted original image is indistinguishable. It can be used for various applications like copyright protection, ownership problems, content verification, authentication and sensitive applications which require high robustness and reversibility of the original content.
Keywords :
copy protection; formal verification; image watermarking; message authentication; PSNR; RDWT-DCT-SVD; authentication application; content verification; copyright protection; correlation based extraction mechanism; extracted original image; format host image; hybrid image watermarking technique; intensity watermark; nonblind watermarking scheme; ownership problem; reversible digital image watermarking technique; robust digital image watermarking technique; sensitive application; trigonometric function; visual quality; Conferences; Discrete cosine transforms; Discrete wavelet transforms; PSNR; Robustness; Watermarking; DCT; NCC; PSNR; SVD; digital watermarking; non-blind; redundant discrete wavelet transform;