Study of Wavelet Functions of Discrete Wavelet Transformation in Image Watermarking

The aim of this paper is to examine a set of wavelet functions (wavelets) used in image watermarking system. Several wavelet functions are used to transform the component detail of the image in frequency domain. Discrete wavelet transform (DWT), discrete Fourier transform (DFT) and discrete cosine transform (DCT) are some commonly used transform domain functions out of which discrete wavelet transform is widely used due to its inherent properties. In this paper, discrete wavelet transform is studied and the salient features of discrete wavelet transform are discussed. Discrete wavelet transform has several wavelet functions associated with it. The properties of various wavelet functions of discrete wavelet transform are discussed and the graphical plots of the wavelet functions are plotted using MATLAB, and a comparative analysis is carried out.