数字信号处理课设基于MATLAB的FFT算法的设计(7)

唐山学院课程设计

for m=1:n

w(m)=exp(-1i*2*pi*(m-1)/N); end p=log2(N);

array1=zeros(1,N,'double'); for q=1:p t1=2^(q-1); t2=2^(p-1); for k=0:(t2/t1-1) for j=0:(t1-1) if mod(q,2)==1

data1=array(k*t1+j+1); data2=array(k*t1+j+t2+1); array1(k*t1*2+j+1)=data1+data2;

array1(k*t1*2+j+t1+1)=(data1-data2)*w(k*t1+1); else

data1=array1(k*t1+j+1); data2=array1(k*t1+j+t2+1); array(k*t1*2+j+1)=data1+data2;

array(k*t1*2+j+t1+1)=(data1-data2)*w(k*t1+1); end end end end

if mod(p,2)==1 return else

array1=array; return end

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唐山学院课程设计

function array=transform_ifft2(array) array=conj(array); [r1,c1]=size(array); for i=1:r1

array(i,:)=transform_fft(array(i,:)); end for i=1:c1

array(:,i)=transform_fft(array(:,i)); end

array=array/(r1*c1);

function pushbutton5_Callback(hObject, eventdata, handles)

[filename, pathname]=uigetfile({'*.jpg;*.tif;*.bmp;*.gif' },'File Selector'); image=imread(strcat(pathname,filename)); scrsz=get(0,'ScreenSize'); set(gcf,'Name','快速傅里叶变换'); axes(handles.axes5); imshow(image); title('原始图像');

function pushbutton6_Callback(hObject, eventdata, handles)

[filename, pathname]=uigetfile({'*.jpg;*.tif;*.bmp;*.gif' },'File Selector'); image=imread(strcat(pathname,filename)); if ndims(image)==3 image=rgb2gray(image); end

scrsz=get(0,'ScreenSize'); set(gcf,'Name','快速傅里叶变换'); axes(handles.axes6); imshow(image); title('灰度图像');

function pushbutton7_Callback(hObject, eventdata, handles)

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唐山学院课程设计

[filename, pathname]=uigetfile({'*.jpg;*.tif;*.bmp;*.gif' },'File Selector'); image=imread(strcat(pathname,filename)); if ndims(image)==3

image=rgb2gray(image); end

scrsz=get(0,'ScreenSize'); set(gcf,'Name','快速傅里叶变换'); [r,c]=size(image); array=image; t=log2(r); t1=floor(t); t2=ceil(t); if t1~=t2

array(2^t2,c)=0; end

[r1,c1]=size(array); t=log2(c1); t3=floor(t); t4=ceil(t); if t3~=t4

array(r1,2^t4)=0; end

[r1,c1]=size(array); n=r1/2;

data_col=zeros(1,n,'double'); %按列方向计算时用到的 for m=1:n

data_col(m)=exp(-1i*2*pi*(m-1)/r1); end n=c1/2;

data_row=zeros(1,n,'double'); %按行方向计算时用到

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唐山学院课程设计

for m=1:n

data_row(m)=exp(-1i*2*pi*(m-1)/r1); end

F=fft2(image); FC=fftshift(F); S=log(1+abs(FC)); axes(handles.axes7); imshow(S,[]); title('内置FFT2结果');

function pushbutton8_Callback(hObject, eventdata, handles)

[filename, pathname]=uigetfile({'*.jpg;*.tif;*.bmp;*.gif' },'File Selector'); image=imread(strcat(pathname,filename)); if ndims(image)==3

image=rgb2gray(image); end

scrsz=get(0,'ScreenSize'); set(gcf,'Name','快速傅里叶变换'); [r,c]=size(image); array=image; t=log2(r); t1=floor(t); t2=ceil(t); if t1~=t2

array(2^t2,c)=0; end

[r1,c1]=size(array); t=log2(c1); t3=floor(t); t4=ceil(t); if t3~=t4

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唐山学院课程设计

array(r1,2^t4)=0; end

[r1,c1]=size(array); n=r1/2;

data_col=zeros(1,n,'double'); %按列方向计算时用到的 for m=1:n

data_col(m)=exp(-1i*2*pi*(m-1)/r1); end n=c1/2;

data_row=zeros(1,n,'double'); %按行方向计算时用到 for m=1:n

data_row(m)=exp(-1i*2*pi*(m-1)/r1); end

F=fft2(image); array=ifft2(F);

array=round(abs(array)); axes(handles.axes8); imshow(array,[]); title('内置IFFT2结果'); return

function pushbutton9_Callback(hObject, eventdata, handles) clc; close all; close(gcf);

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