This paper discusses the application of complex discrete wavelet transform (CDWT) which has significant advantages over real wavelet transform for certain signal processing problems. CDWT is a form of discrete wavelet transform, which generates complex coefficients by using a dual tree of wavelet filters to obtain their real and imaginary parts. The paper is divided into three sections. The fir...

Edge detection improves image readability and it is an important part of images preprocessing aimed to their segmentation and automatic recognition of their contents. This paper describes selected methods of edge detection in magnetic resonance images, with the emphasis on the wavelet transform use. The first part briefly describes the mathematical background of the wavelet transform, including...

The aim of this paper is a complete statistical analysis of the two dimensional discrete wavelet transform, 2D DWT. This analysis represents a generalization of the statistical analysis of the 1D DWT, already reported in literature. The probability density function, the correlation and the first two moments of the coefficients of the 2D-DWT are computed. The asymptotic behaviour of this transfo...

This study presents a framework for gray texture classification based on wavelet and curvelet features. The two main frequency domain transformations Discrete Wavelet Transform (DWT) and Discrete Curvelet Transform (DCT) are analyzed. The features are extracted from the DWT and DCT decomposed image separately and their performances are evaluated independently. The performance metric used to ana...

In this paper we discuss several issues relevant to the parallel implementation of a 2-D Discrete Wavelet Transform (DWT) on general purpose multiprocessors. Our interest in this transform is motivated by its usage in an image fusion application which has to manage large image sizes, making parallel computing highly advisable. We have also paid much attention to memory hierarchy exploitation, s...

Recently, it was suggested that spectrum estimation can be accomplished by applying wavelet denoising methodology to wavelet packet coefficients derived from the logarithm of a spectrum estimate. The particular algorithm we consider consists of computing the logarithm of the multitaper spectrum estimator, applying an orthonormal transform derived from a wavelet packet tree to the log multitaper...

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 tr...

Video copyright protection is the most generally acknowledged method of preventing data piracy. This paper proposes a blind video technique based on Fast Walsh Hadamard Transform (FWHT), Discrete Wavelet (DWT), and Arnold Map. The proposed chooses only frames with maximum minimum energy features to host watermark. It also exploits advantages both fast transform (FWHT) discrete wavelet transform...

Due to the lack of invariant property of discrete wavelet transform (DWT), the DWT based watermarking schemes are relatively vulnerable to the watermarking attacks such as geometric variations (i.e., rotation and translation etc.). To improve the reliability of the DWT based watermark detection, this paper introduces the new multiresolution based image registration method that is used to recove...

The dual-tree complex wavelet transform (CWT) is a relatively recent enhancement of the discrete wavelet transform (DWT) with important additional properties: It is nearly shift-invariant and directionally selective in two and higher dimensions. It achieves this with a redundancy factor of only 2 for d-dimensional signals, which is substantially lower than the undecimated DWT. The multidimensio...