Effect of Varying Embedding Energy and Energy wise Sorting on Watermarking using Wavelet Transforms of Orthogonal Transforms DCT, Walsh and Haar

This paper proposes a robust watermarking technique using wavelets of well-known transforms DCT, Walsh and Haar. HL and LH bands are separately selected for watermark insertion. While inserting watermark, its energy is varied with 40% margin to original energy of region of host selected for insertion of watermark to study effect on robustness. Performance of proposed technique is evaluated against cropping, compression, noise addition, image resizing and histogram equalization attacks and compared for varying embedding energy. Increasing embedding energy leads to improved robustness as well as sometimes marginal improvement in imperceptibility when various attacks are performed on watermarked image. This performance is also found to be better than use of orthogonal transforms DCT, Walsh and Haar as proposed in our previous work and use of wavelets without energy-wise sorting of middle frequency coefficients. Keywords— Watermarking, DCT, Walsh, Haar, wavelet transforms.