Performance Comparison of Wavelets Generated from Four Different Orthogonal Transforms for Watermarking With Various Attacks

Abstract

This paper proposes a watermarking technique using different orthogonal wavelet transforms like Hartley wavelet, Kekre
wavelet, Slant wavelet and Real Fourier wavelet transform generated from corresponding orthogonal transform. These
orthogonal wavelet transforms have been generated using different sizes of component orthogonal transform matrices.
For example 256*256 size orthogonal wavelet transform can be generated using 128*128 and 2*2 size component
orthogonal transform. It can also be generated using 64*64 and 4*4, 32*32 and 8*8, 16*16 and 16*16 size component
orthogonal transform matrices. In this paper the focus is to compare the performance of above mentioned transforms
generated using 128*128 and 2*2 size component orthogonal transform and 64*64 and 4*4 size component orthogonal
transform in digital image watermarking. The other two combinations are not considered as their performance is
comparatively not as good. Comparison shows that wavelet transforms generated using (128,2) combination of orthogonal transform give better performances than wavelet transforms generated using (64,4) combination of orthogonal
transformfor contrast stretching, cropping, Gaussian noise, histogram equalization and resizing attacks. Real Fourier
wavelet and Slant wavelet prove to be better for histogram equalization and resizing attack respectively than DCT wavelet
and Walsh wavelet based watermarking presented in previous work.