数字信号处理课设基于MATLAB的FFT算法的设计(5)

唐山学院课程设计

附录I

function image_process_FFT()

[filename, pathname]=uigetfile({'*.jpg;*.tif;*.bmp;*.gif' },'File Selector'); image=imread(strcat(pathname,filename)); scrsz=get(0,'ScreenSize');

figure('position',[0 0 scrsz(3)-1 scrsz(4)]); set(gcf,'Name','快速傅里叶变换'); subplot(2,4,1); imshow(image); title('原始图像'); subplot(2,4,5); imshow(image); title('原始图像'); if ndims(image)==3

image=rgb2gray(image); end

scrsz=get(0,'ScreenSize'); set(gcf,'Name','快速傅里叶变换'); subplot(2,4,2); imshow(image); title('灰度图像'); subplot(2,4,6); imshow(image); title('灰度图像'); [r,c]=size(image); array=image; t=log2(r); t1=floor(t); t2=ceil(t);

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唐山学院课程设计

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 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)); subplot(2,4,3); imshow(S1,[]);

title('自建FFT2函数结果'); array=transform_ifft2(array); array=abs(array); array=array(1:r,1:c);

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唐山学院课程设计

subplot(2,4,4); imshow(array,[]); title('自建IFFT2结果'); F=fft2(image); FC=fftshift(F); S=log(1+abs(FC)); subplot(2,4,7) imshow(S,[]); title('内置FFT2结果'); array=ifft2(F);

array=round(abs(array)); subplot(2,4,8); imshow(array,[]); title('内置IFFT2结果'); return

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

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唐山学院课程设计

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

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);

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唐山学院课程设计

附录II

function varargout = untitled2(varargin) gui_Singleton = 1;

gui_State = struct('gui_Name', mfilename, ... 'gui_Singleton', gui_Singleton, ...

'gui_OpeningFcn', @untitled2_OpeningFcn, ... 'gui_OutputFcn', @untitled2_OutputFcn, ... 'gui_LayoutFcn', [] , ... 'gui_Callback', []); if nargin && ischar(varargin{1})

gui_State.gui_Callback = str2func(varargin{1}); end if nargout

[varargout{1:nargout}] = gui_mainfcn(gui_State, varargin{:}); else

gui_mainfcn(gui_State, varargin{:}); end

function untitled2_OpeningFcn(hObject, eventdata, handles, varargin) handles.output = hObject; guidata(hObject, handles);

function varargout = untitled2_OutputFcn(hObject, eventdata, handles) varargout{1} = handles.output;

function pushbutton1_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.axes1); imshow(image);

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