Wavelet transforms versus Fourier transforms
نویسندگان
چکیده
منابع مشابه
Continuous quaternion fourier and wavelet transforms
It is well-known that every two dimensional rotation around the origin in the plane R can be represented by the multiplication of the complex number e = cos θ + i sin θ, 0 ≤ θ < 2π. Similarly, every three dimensional rotation in the space R can be represented by the multiplications of the quaternion q from the left-hand side and its conjugate q̄ from the right-hand side, where q = cos(θ/2) + α s...
متن کاملSpeech steganography using wavelet and Fourier transforms
A new method to secure speech communication using the discrete wavelet transforms (DWT) and the fast Fourier transform is presented in this article. In the first phase of the hiding technique, we separate the speech high-frequency components from the low-frequency components using the DWT. In a second phase, we exploit the low-pass spectral proprieties of the speech spectrum to hide another sec...
متن کاملClassical Wavelet Transforms over Finite Fields
This article introduces a systematic study for computational aspects of classical wavelet transforms over finite fields using tools from computational harmonic analysis and also theoretical linear algebra. We present a concrete formulation for the Frobenius norm of the classical wavelet transforms over finite fields. It is shown that each vector defined over a finite field can be represented as...
متن کاملComparison of Discrete Cosine Transforms (DCT), Discrete Fourier Transforms (DFT), and Discrete Wavelet Transforms (DWT) in Digital Image Watermarking
Digital Image Watermarking is used recently to secure the image by embedding another digital image. It is typically used to identify ownership of the copyright of the signal. Frequency domain transformation methods used widely in Digital Image Compression and Digital Image Watermarking. They reduce the weakness of classics digital image watermarking such as Least Significant Bit (LSB) methods w...
متن کاملSparse Generalized Fourier Transforms ∗
Block-diagonalization of sparse equivariant discretization matrices is studied. Such matrices typically arise when partial differential equations that evolve in symmetric geometries are discretized via the finite element method or via finite differences. By considering sparse equivariant matrices as equivariant graphs, we identify a condition for when block-diagonalization via a sparse variant ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Bulletin of the American Mathematical Society
سال: 1993
ISSN: 0273-0979
DOI: 10.1090/s0273-0979-1993-00390-2