Wavelet transforms are multiresolution decompositions that can be used to analyze signals and images. The wavelet representation is inherently hierarchical, making it an excellent choice for building scalable codecs. In this report, we address the compression of still and moving images using wavelet-based methods. The discussion will be centered on two issues: performance evaluation and multire...

The aim of this paper is to examine a set of wavelet functions (wavelets) for implementation in a still image compression system and to highlight the benefit of this transform relating to today’s methods. The paper discusses important features of wavelet transform in compression of still images, including the extent to which the quality of image is degraded by the process of wavelet compression...

In this paper, we present a new speech perceptual hashing authentication algorithm based on wavelet packet decomposition (WPD) for speech content authentication. Firstly, a wavelet packet coefficients matrix of wavelet reconstruction is generated from an original speech signal after high frequency pre-processing followed by wavelet packet decomposition. Secondly, the wavelet packet coefficients...

—This paper proposes an edge detection algorithm based on adaptive threshold which is obtained by histogram matching edge gradient value. The implementation of this algorithm is made up of three procedures: all phase discrete cosine sequency filtering, wavelet decomposition and adaptive threshold processing. The image is decomposed into low frequency and high frequency subbands by using all ph...

A method is presented for the compression of biomedical images using in place of the discrete cosine transform (DCT) the discrete orthogonal Gauss-Hermite transform (DOGHT). The latter expands the signals on a basis of Gauss-Hermite functions instead of the cosine functions and leads, in many practical cases, to 2-3 times better compression for the same reconstruction error as the DCT. This is ...

Hilbert transform (HT) is an important tool in constructing analytic signals for various purposes, such as envelope and instantaneous frequency analysis, amplitude modulation, shift invariant wavelet analysis and Hilbert-Huang decomposition. In this work we introduce a method for computation of HT based on the discrete cosine transform (DCT). We show that the Hilbert transformed signal can be o...

The Fourier transform has been used as a reliable tool in signal analysis for many years. Invented in the early 1800s by its namesake, Jean Baptiste Joseph Fourier, the Fourier transform has become a cornerstone of modern signal analysis. The Fourier transform has proven incredibly versatile in applications ranging from patten recognition to image processing. Nevertheless, it suuers from certai...

Face Recognition has been identified as one of the attracting research areas and it has drawn the attention of many researchers due to its varying applications such as identity authentication, security access control human computer interaction and surveillance. In this paper, we compare different features extraction algorithms like Principal Component Analysis (PCA), Discrete Cosine Transform (...

The proliferation of digital audio file is costing loss of revenue to the owner of copyright information especially in the music industry. The paper brings to view works done by various on digital audio watermarking and using discrete wavelet transform (DWT) and discrete cosine transform (DCT) with chaotic watermarking towards carrying out investigation for real life application.

In this paper, the PSNR performance of conventional discrete cosine transform (DCT) OFDM system is compared with discrete wavelet transform (DWT)-OFDM system. We use different error correcting codes viz; Reed Solomon, LDPC, DCT and DWT. KeywordsDCT, DWT, OFDM, Reed Solomon, LDPC.