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Description: 矩阵运算处理,包括FFT,IFFT,FFTSHIFT等
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Size: 2714 |
Author: yz |
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Description: 用C++实现了MATLAB中fftshift及triang函数功能,代码是实现此二功能的函数
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Size: 5412 |
Author: 李明 |
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Description: matlab中应用小波变换的几个程序
包括cwt,dwt,fft,fftshift的使用
版本为matlab7.0
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Size: 2377 |
Author: 杨青禾 |
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Description: ch4_1_4:对f进行补零(区域大小为256×256),而后进行二维快速傅立叶变换(§4.1.2)
ch4_1_5:使变换结果的零频率分量位于中心,调用函数fftshift(§4.1.2)
ch4_1_6:利用函数ifft2对乘积进行傅立叶反变换(§4.1.3)
ch4_1_7:得到在图像text.png中对应字母“a”的定位结果(§4.1.3)
ch4_2_1:对一幅图像进行离散余弦变换(§4.2.1)
ch4_2_2:JPEG图像压缩(§4.2.2)
ch4_3_1:正方形图像在0°和45°方向上的Radon变换(§4.3.1)
ch4_3_2:计算方形图像从0°到180°每隔1°计算一次Radon变换的命令(§4.3.1)
ch4_3_3:直线检测(§4.3.1)
ch4_3_4:利用radon函数和iradon函数构造一个简单图像的投影并重建图像(§4.3.2)
ch4_4_1:映射和重建图像(§4.4.1)
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Size: 4208 |
Author: sherman1944 |
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Description: 矩阵运算处理,包括FFT,IFFT,FFTSHIFT等-Matrix processing, including FFT, IFFT, FFTSHIFT, etc.
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Size: 2048 |
Author: yz |
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Description: 用C++实现了MATLAB中fftshift及triang函数功能,代码是实现此二功能的函数-With C++ Achieved in MATLAB function fftshift and triang function code is to achieve a function of these two functions
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Size: 5120 |
Author: 李明 |
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Description: matlab中应用小波变换的几个程序
包括cwt,dwt,fft,fftshift的使用
版本为matlab7.0-Application of wavelet transform matlab several procedures, including cwt, dwt, fft, fftshift use version matlab7.0
Platform: |
Size: 2048 |
Author: 杨青禾 |
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Description: ch4_1_4:对f进行补零(区域大小为256×256),而后进行二维快速傅立叶变换(§4.1.2)
ch4_1_5:使变换结果的零频率分量位于中心,调用函数fftshift(§4.1.2)
ch4_1_6:利用函数ifft2对乘积进行傅立叶反变换(§4.1.3)
ch4_1_7:得到在图像text.png中对应字母“a”的定位结果(§4.1.3)
ch4_2_1:对一幅图像进行离散余弦变换(§4.2.1)
ch4_2_2:JPEG图像压缩(§4.2.2)
ch4_3_1:正方形图像在0°和45°方向上的Radon变换(§4.3.1)
ch4_3_2:计算方形图像从0°到180°每隔1°计算一次Radon变换的命令(§4.3.1)
ch4_3_3:直线检测(§4.3.1)
ch4_3_4:利用radon函数和iradon函数构造一个简单图像的投影并重建图像(§4.3.2)
ch4_4_1:映射和重建图像(§4.4.1)
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Size: 4096 |
Author: sherman1944 |
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Description: 计算全息close all clc clear
A=zeros(64)
A(15:20,20:40)=1 A(15:50,20:25)=1
A(45:50,20:40)=1 A(30:34,20:35)=1
% ppp=exp(rand(64)*pi*2*i) A=A.*ppp
% Author s email: zjliu2001@163.com
figure imshow(abs(A),[])
Fa=fft2(fftshift(A)) Fs=fftshift(Fa)
Am=abs(Fs) % amplitude
Ph=angle(Fs) % phase
s=11 % 这表示边长吗?
cgh=zeros(64*s)
th=max(max(abs(Fs)))
-CGH close all clc clearA = zeros (64) A (15:20,20:40) = 1 A (15:50,20:25) = 1 A (45:50,20:40) = 1 A (30 : 34,20:35) = 1 ppp = exp (rand (64)* pi* 2* i) A = A.* ppp Author s email: zjliu2001@163.comfigure imshow (abs (A), [] ) Fa = fft2 (fftshift (A)) Fs = fftshift (Fa) Am = abs (Fs) amplitudePh = angle (Fs) phases = 11 This means that the length was it? cgh = zeros (64* s) th = max (max (abs (Fs)))
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Size: 3072 |
Author: ccfu |
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Description: ch4_1_1:矩形连续函数的傅立叶变换(§4.1.1)
ch4_1_2:构建一个矩形函数(§4.1.2)
ch4_1_3:对f进行二维快速傅立叶变换(§4.1.2)
ch4_1_4:对f进行补零(区域大小为256×256),而后进行二维快速傅立叶变换(§4.1.2)
ch4_1_5:使变换结果的零频率分量位于中心,调用函数fftshift(§4.1.2)
-ch4_1_1: rectangular continuous function of the Fourier transform (§ 4.1.1) ch4_1_2: to build a rectangular function (§ 4.1.2) ch4_1_3: of f for two-dimensional fast Fourier transform (§ 4.1.2) ch4_1_4: for f to zero (region size of 256 × 256), and then carry out two-dimensional fast Fourier transform (§ 4.1.2) ch4_1_5: Transform the results so that the zero-frequency component at the center, call the function fftshift (§ 4.1.2)
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Size: 4096 |
Author: 汤跃峰 |
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Description: matlab实例clearN=100f=zeros(50,50) f(15:35,23:28)=1 figure(1)imshow(f, notruesize )F=fft2(f,N,N) F2=fftshift(abs(F)) figure(2)x=1:N y=1:N mesh(x,y,F2(x,y)) colormap(gray) colorbar-matlab
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Size: 4096 |
Author: 孙强 |
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Description: Transmit 2 signals via DSB-SC AM
Fs= 44.1 KHz , fft fftshift
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Size: 16633856 |
Author: manos |
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Description: :滤波
fs=400 采样频率,必须大于两倍基带信号最高频率
ts=1/fs 采样时间间隔
T=5 时间窗大小
t=0:ts:T -hf1=zeros(1,N)
hf1(f<=B1&f>=-B1)=1
y1=hf1.*fftshift(y)
figure
subplot(211)
plot(f,abs(fftshift(y))/N,f,hf1, r-- )
axis([-fs/2,fs/2,0,1.2])
title( 原信号频谱 )
xlabel( f /Hz )
subplot(212)
plot(f,abs(y1)/N)
title( 低通滤波,截止频率90Hz )
xlabel( f /Hz )
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Size: 1024 |
Author: 张红 |
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Description: 例3:分析占空比为ta的矩形脉冲频谱
T=1 时间窗大小
ta=0.5 占空比
N=256
t=linspace(-T,T,N)
ts=2*T/N
fs=1/ts
-x=zeros(1,N)
x(N/2-round(N/2*ta):N/2+round(N/2*ta))=ones(1,2*round(N/2*ta)+1)
y=fft(x,N)
figure
plot(t,x)
title([ 时域信号图 占空比为 ,num2str(ta)])
axis([-T T-0.2 1.2])
xlabel( t /s )
figure
subplot(211)
f=linspace(-fs/2,fs/2,N)
plot(f,abs(fftshift(y))/N)
title([ 矩形脉冲双边谱 脉冲时间t=[- ,num2str(ta*T), , ,num2str(ta*T), ] ])
xlabel( f /Hz )
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Size: 1024 |
Author: 张红 |
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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.
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Size: 1024 |
Author: linve |
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Description: f=zeros(30,30)
f(5:24,13:17)=1
imshow(f, notruesize )
F=fft2(f,256,256)
F2=fftshift(F)
figure,imshow(log(abs(F2)),[-1 5], notruesize ) -f=zeros(30,30)
f(5:24,13:17)=1
imshow(f, notruesize )
F=fft2(f,256,256)
F2=fftshift(F)
figure,imshow(log(abs(F2)),[-1 5], notruesize )
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Size: 35840 |
Author: madlain |
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Description: 矩形连续函数的傅立叶变换:构建一个矩形函数,对f进行补零,而后进行二维快速傅立叶变换:使变换结果的零频率分量位于中心,调用函数fftshift:映射和重建图像-Fourier transform of rectangular continuous function: for a rectangular function, the zeros of f, then the two-dimensional fast Fourier transform: the transform results of the zero-frequency components in the center, call the function fftshift: mapping and image reconstruction
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Size: 5120 |
Author: edy |
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Description: 利用函数建立非负矩形脉冲,然后利用频谱分析函数对该矩形脉冲进行频谱分析,并进行频率移位修正(利用FFTSHIFT),观察该脉冲频谱。-Use function to create a non-negative rectangular pulse, and then use the spectral analysis of the rectangular pulse function spectral analysis, and the frequency shift correction (using FFTSHIFT), observed that the pulse spectrum.
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Size: 1024 |
Author: 趁黑 |
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Description: 在数字信号处理中dft是最常使用的一个数学变换,但是大家总是在使用而没有深入的廖家,老外这篇文章感觉还行,给大家参考下-Dft digital signal processing is the most common use of a mathematical transformation, but we are always in use without depth Liao, foreigners this article feeling okay for everyone to refer to the following
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Size: 102400 |
Author: jljlg |
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Description: 主要是用c语言实现matlab中的fftshift函数的,-Mainly used c language matlab in fftshift function,
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Size: 761856 |
Author: 霹雳风暴001 |
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