Description: Description: Recent studies on Mathematical modeling of visual cortical cells [Kulikowski/Marcelja/Bishop:1982] suggest a tuned band pass filter bank structure. These filters are found to have Gaussian transfer functions in the frequency domain. Thus, taking the Inverse Fourier Transform of this transfer function we get a filter characteristics closely resembling to the Gabor filters. The Gabor filter is basically a Gaussian (with variances sx and sy along x and y-axes respectively) modulated by a complex sinusoid (with centre frequencies U and V along x and y-axes respectively). Platform: |
Size: 2048 |
Author:gz |
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Description: This award winning library is a C library for "computing the Discrete Fourier Transform (DFT) in one or more dimensions, of both real and complex data, and of arbitrary input size." -This award winning library is a C library az r "computing the Discrete Fourier Transform (D FT) in one or more dimensions, of both real and complex data. and of arbitrary input size. " Platform: |
Size: 2736128 |
Author:王云 |
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Description: 汽车牌照定位与字符识别。这种方法总体上比较容易理解,Matlab的函数隐藏了傅立叶变换等复杂的计算。-Vehicle license positioning and character recognition. This method is easier to understand in general, Matlab function to hide the complex Fourier Transform calculations. Platform: |
Size: 70656 |
Author:王博 |
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Description: FFTW, a collection of fast C routines to compute the Discrete
Fourier Transform in one or more dimensions.The fftw/ directory contains the source code for the complex transforms,
and the rfftw/ directory contains the source code for the real transforms. Platform: |
Size: 1546240 |
Author:北科 |
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Description: Radix-2 Fast Fourier Transform, real or complex sin/cos transform
-Radix-2 Fast Fourier Transform, real or complex sin/cos transform Platform: |
Size: 40960 |
Author:dai |
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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: 复数的傅里叶变换与反变换,虚部与实部分开运算,并根据标志位判断是正变换还是反变换
-Complex Fourier transform and inverse transform, the imaginary part and real part of the open operation and in accordance with flag bit to determine is positive transformation or the inverse transform Platform: |
Size: 1024 |
Author:jinanzht |
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Description: Program FFT.FOR
This FORTRAN program calculates the fast Fourier transform of a
timeseries (real and/or complex) or the inverse Fourier transform
of spectral components (real and/or complex). The FFT is based
on the algorithm given in Numerical Recipes, Cambridge University
Press, 1994.-Program FFT.FOR
This FORTRAN program calculates the fast Fourier transform of a
timeseries (real and/or complex) or the inverse Fourier transform
of spectral components (real and/or complex). The FFT is based
on the algorithm given in Numerical Recipes, Cambridge University
Press, 1994. Platform: |
Size: 71680 |
Author:梦回 |
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Description: The real and imaginary components of a complex Gabor filter are phase sensitive,
i.e., as a consequence their response to a sinusoid is another sinusoid (see Figure
1.2). By getting the magnitude of the output (square root of the sum of squared
real and imaginary outputs) we can get a response that phase insensitive and thus
unmodulated positive response to a target sinusoid input (see Figure 1.2). In some
cases it is useful to compute the overall output of the two out of phase filters.
One common way of doing so is to add the squared output (the energy) of each
filter, equivalently we can get the magnitude. This corresponds to the magnitude
(more precisely the squared magnitude) of the complex Gabor filter output. In the
frequency domain, the magnitude of the response to a particular frequency is simply
the magnitude of the complex Fourier transform, i.e. Platform: |
Size: 159744 |
Author:cestrada |
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Description: This source code is the 32point FFT(Fast Fourier Transform) for Real Time sampling system (like PQ meter or Digital Relay). The complex computation is realized without complex.h in this code, based on only C. -This source code is the 32point FFT(Fast Fourier Transform) for Real Time sampling system (like PQ meter or Digital Relay). The complex computation is realized without complex.h in this code, based on only C. Platform: |
Size: 644096 |
Author:kriskim |
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Description: fftshift 比较实数和复数傅里叶变换频谱的不同,以及N取值对其频谱特点的影响。-fftshift more real and complex Fourier transform spectrum of different, and the N values of the characteristics of its spectrum. Platform: |
Size: 1024 |
Author:linve |
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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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Description: 通过Matlab求出连续时间信号的傅立叶变换及编程绘制各种连续时间信号系统的时域波行,幅度谱以及相位谱-Fourier transform of continuous-time signal obtained through Matlab and programming time domain wave line to draw a variety of continuous-time signal system , the amplitude spectrum and phase spectrum
Platform: |
Size: 12288 |
Author:杨菲 |
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Description: 分数傅里叶变换是解决在频域或者时域内无法运算的复杂信号处理,这是收藏的经典分数傅里叶变换论文,有一定参考价值-Fractional Fourier transform is the solution to deal with complex signals in the frequency domain or time domain operation, this is a classic collection of fractional Fourier transform paper, a certain reference value Platform: |
Size: 2838528 |
Author:LILI |
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Description: 在stm32f407上利用官方的库文件进行复数的傅里叶变换-The use of official documents in the library performs a complex Fourier transform stm32f407 Platform: |
Size: 10103808 |
Author:许睿 |
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Description: 该程序是复数傅里叶变化和汉明窗参数的产生已经频谱搬移,程序简单易懂。-The program include complex Fourier transform and Hamming window parameter generation and spectrum shifting, this program are simple and easy to understand. Platform: |
Size: 1024 |
Author:gaofang |
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