Description: 1．通过实验加深对快速傅立叶变换（FFT）基本原理的理解。
2．了解FFT点数与频谱分辨率的关系，以及两种加长序列FFT与原序列FFT的关系。
离散傅里叶变换（DFT）和卷积是信号处理中两个最基本也是最常用的运算，它们涉及到信号与系统的分析与综合这一广泛的信号处理领域。实际上卷积与DFT之间有着互通的联系：卷积可化为DFT来实现，其它的许多算法，如相关、滤波和谱估计等都可化为DFT来实现，DFT也可化为卷积来实现。-1. Deepen the experimental fast Fourier transform (FFT) the basic tenets of understanding. 2. Understand the FFT spectrum and points of the resolution, and two extended sequence with the original FFT FFT relations. Discrete Fourier Transform (DFT) and the convolution of two signal processing is the most commonly used basic arithmetic, they relate to the signal and system analysis and synthesis of the wide range of signal processing field. DFT actually convolution and interoperability between contact : DFT into convolution can be achieved in many other algorithms, If relevant, filtering and spectral estimation could be achieved as DFT, DFT into convolution can be achieved. Platform: |
Size: 3072 |
Author:深蓝 |
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Description: 实现一维快速傅里叶变换，采用蝶形算法进行频域变换；
二维快速傅立叶变换在此基础上进行，调用两次一维快速傅里叶变换即可。-achieve a fast Fourier transform, using butterfly frequency domain algorithm transformation; two-dimensional fast Fourier transform on this basis, call a two-dimensional fast Fourier transforms. Platform: |
Size: 1024 |
Author:cxr |
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Description: 在滤波和信号处理中，利用matlab功能实现二维快速傅里叶变换-In filtering and signal processing using matlab function realization of two-dimensional fast Fourier transform Platform: |
Size: 109568 |
Author:小蔡 |
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Description: The frequency domain plays an important role in image
processing to smooth, enhance, and detect edges of images. Although
image data typically does not include imaginary values, the fast Fourier
transform (FFT) has been used for obtaining spectra. In this paper,
the fast Hartley transform (FHT) is used to transform two-dimensional
image data. Because the Hartley transform is real valued, it does
not require complex operations. Both spectra and autocorrelations of
two-dimensional ultrasound images of normal and abnormal livers were
computed. Platform: |
Size: 4096 |
Author:archit |
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Description: 本实验要求开发一个2-D FFT程序包，使其可以应用于后续的几个实验。这个程序需要完成的功能是用因子（-1）^(x+y)乘以输入图像以实现滤波的中心变换，并还要求用一个实矩阵乘以一个复数矩阵通过调用两个图像的乘法程序来实现对应元素的相乘，同时计算反傅立叶变换，得到的结果乘以（-1）^(x+y)并取其实部最后计算频谱。实验中用到傅立叶变换的基本公式，通过实验我们可以更加深刻的理解频域滤波的基础。-The experiment calls for the development of a 2-D FFT package so that it can be applied to a number of follow-up experiment. This process needs to be done is to factor the function (-1) ^ (x+ y) multiplied by the input image to achieve the center of filter change, and also requires a real matrix multiplied by a complex matrix by calling the two images of the multiplication process to achieve multiplication of the corresponding elements, calculating the anti-Fourier transform at the same time, the result multiplied by (-1) ^ (x+ y) and check the final calculation of the Department of the spectrum in fact. Fourier transform experiment used the basic formula, we can experiment more profound understanding of the basis of frequency domain filtering. Platform: |
Size: 142336 |
Author:jhm |
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Description: 二维傅里叶变换,对图像进行二维傅里叶变换处理-Two-Dimensional Fast Fourier Transform
The purpose of this project is to develop a 2-D FFT program "package" that will be used
in several other projects that follow. Your implementation must have the capabilities to:
(a) Multiply the input image by (-1)x+y to center the transform for filtering.
(b) Multiply the resulting (complex) array by a real function (in the sense that the
the real coefficients multiply both the real and imaginary parts of the transforms).
Recall that multiplication of two images is done on pairs of corresponding elements.
(c) Compute the inverse Fourier transform.
(d) Multiply the result by (-1)x+y and take the real part.
(e) Compute the spectrum. Platform: |
Size: 1024 |
Author:solo |
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Search - MATLAB Two-Dimensional Fast Fourier Transform