IJSRP, Volume 5, Issue 12, December 2015 Edition [ISSN 2250-3153]
Shveti Sejpal, Dr. Nikesh Shah
This paper presents a blind digital image watermark embedding technique and its comparative performance analysis based on Discrete Wavelet Transform (DWT) domain for hiding little but important information in cover image. In order to confirm to human perception characteristics, this approach uses two frequency sub-bands HL and HH of DWT to embed a multi-bit watermark image. Here to achieve better robustness and perceptual quality the watermark bits are distributed to the wavelet coefficients of the image edges in every selected sub-band. Here for DWT decomposition simple, orthogonal, symmetric ‘Haar’ wavelet is used. Here gain factor K=0.55 is selected for testing the performance under several attacks. In DWT domain good perceptual quality is achieved with PSNR value 29.7493, SSIM value 0.9451 and NC value 0.9831. We further demonstrated that our technique is robust against several filter attacks and noise addition.