Journal ArticleDOI
On asymmetrical performance of discrete cosine transform
Ali N. Akansu,Richard A. Haddad +1 more
TLDR
The authors explain theoretically this asymmetrical performance of the DCT as well as the behavior of the modified Hermite transform (MHT) and the discrete Hadamard transform (DHT), which perform symmetrically regardless of the sign of the autocorrelation coefficient.Abstract:
The discrete cosine transform (DCT) is considered as a suboptimum transform for many practical source-coding applications. Autoregressive order 1 (AR(1)) source models are good first approximations to several natural signals. It is known that the performance of the DCT depends on the sign of the autocorrelation coefficient of the AR(1) source. The authors explain theoretically this asymmetrical performance of the DCT as well as the behavior of the modified Hermite transform (MHT) and the discrete Hadamard transform (DHT), which perform symmetrically regardless of the sign of the autocorrelation coefficient. >read more
Citations
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Journal ArticleDOI
Extended lapped transforms: properties, applications, and fast algorithms
TL;DR: In this article, the extended lapped transform (ELT) is introduced, as a generalization of the previously reported modulated Lapped Transform (MLT), which is a promising substitute for traditional block transforms in transform coding systems.
Journal ArticleDOI
Texture Classification by Modeling Joint Distributions of Local Patterns With Gaussian Mixtures
TL;DR: This work shows that combining the LBP difference filters with the GMM-based density estimator outperforms the classical LBP approach and its codebook extensions and extends this texture descriptor to achieve full invariance to rotation.
Proceedings ArticleDOI
Extended lapped transforms: fast algorithms and applications
TL;DR: In this paper, an extended lapped transform (ELT) based on a type-IV discrete cosine transform (DCT-IV) is proposed for AR (autoregressive) signals and also for real speech signals.
Book ChapterDOI
Chapter 2 – Orthogonal Transforms
Ali N. Akansu,Richard A. Haddad +1 more
TL;DR: In this article, the authors introduce the concept of orthogonal transforms, which decompose a batch of correlated signal samples into a set of uncorrelated spectral coefficients, with energy concentrated in as few coefficients as possible.
References
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Journal ArticleDOI
Discrete Cosine Transform
TL;DR: In this article, a discrete cosine transform (DCT) is defined and an algorithm to compute it using the fast Fourier transform is developed, which can be used in the area of digital processing for the purposes of pattern recognition and Wiener filtering.
Journal ArticleDOI
A new orthogonal transform for signal coding
Richard A. Haddad,Ali N. Akansu +1 more
TL;DR: The authors propose an orthogonal, unitary transformation called the modified Hermite transformation (MHT) and its extension, which is called the modular modified Hermites transformation (MMHT), which is efficient computationally and comparable to the DCT for AR(1) source models with positive correlation coefficients.