A modified blind image watermarking scheme based on DWT, DCT and SVD domain using GA to optimize robustness

Abstract

A modified blind image watermarking algorithm using discrete wavelet transform (DWT), discrete cosine transform (DCT) and singular value decomposition (SVD) is proposed in this paper. One level DWT operation is performed on original host image using Haar wavelet and approximation (LL) sub-band is selected to split it into two sub images. DCT and SVD operations are performed in both sub images using 8×8 block size. Based on pixels values of binary watermark image, singular value of first sub image is modified referring singular value of second sub image to embed watermark. Genetic algorithm (GA) technique is adopted to optimize visual quality and robustness of watermarked image. Peak Signal to Noise Ratio (PSNR) and Normalized Cross correlation (NCC) are computed to evaluate imperceptibility and robustness of the watermarked image. Experimental results obtained confirm that the proposed method is efficient and more robust against different attacks, viz. noise insertion, filtering, JPEG compression, histogram equalization, gamma correction, bit plane removal, image sharpening and cropping attacks.