唐山学院课程设计
title('原始图像');
function pushbutton2_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.axes2); imshow(image); title('灰度图像');
function pushbutton3_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);
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唐山学院课程设计
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 for m=1:n
data_row(m)=exp(-1i*2*pi*(m-1)/r1); end
array=transform_fft2(array); Ft=fftshift(array); S1=log(1+abs(Ft)); axes(handles.axes3); imshow(S1,[]);
title('自建FFT2函数结果'); function array=transform_fft2(array) array=double(array); [r1 c1]=size(array); for j=1:r1
array(j,:)=transform_fft(array(j,:)); end for j=1:c1
array(:,j)=transform_fft((array(:,j)));
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唐山学院课程设计
end
function array1=transform_fft(array) N=length(array); n=N/2;
w=zeros(1,n,'double'); 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
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唐山学院课程设计
return else
array1=array; return end
function pushbutton4_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
array(r1,2^t4)=0; end
[r1,c1]=size(array); n=r1/2;
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唐山学院课程设计
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
array=transform_fft2(array); array=transform_ifft2(array); array=abs(array); array=array(1:r,1:c); axes(handles.axes4); imshow(array,[]); title('自建IFFT2结果'); return
function array=transform_fft2(array) array=double(array); [r1 c1]=size(array); for j=1:r1
array(j,:)=transform_fft(array(j,:)); end for j=1:c1
array(:,j)=transform_fft((array(:,j))); end
function array1=transform_fft(array) N=length(array); n=N/2;
w=zeros(1,n,'double');
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