www.gusucode.com > IPCV_Eval_Kit_R2019a_0ce6858工具箱matlab程序源码 > IPCV_Eval_Kit_R2019a_0ce6858/code/demo_files/I2_10_2a_fft2.m

    %% 2師尦偺崅懍僼乕儕僄曄姺偺僨儌
clear;clc;close all;imtool close all

%% 256x256偺僥僗僩夋憸偺惗惉
I = zeros(256,256);   % 梫慺0偱[256峴,256楍]偺峴楍偺惗惉
I(5:24,13:17) = 1;    % 嵍忋偵敀偄椞堟傪嶌惉
figure;imshow(I);

%% 2師尦偺FFT寁嶼丗嵍忋嬿偑僛儘廃攇悢學悢(DC惉暘)
F = fft2(I);
figure;imshow(log(abs(F)), [-1 5]);colormap(jet); colorbar;    % DC惉暘偑嵍忋嬿

%% fftshift娭悢傪梡偄丄僛儘廃攇悢學悢(DC惉暘)傪嵍忋嬿偐傜丄拞怱傊堏摦
%     戞堦徾尷偲戞嶰徾尷丄戞擇徾尷偲戞巐徾尷傪擖傟懼偊
Fs = fftshift(F);
figure;imshow(log(abs(Fs)), [-1 5]);colormap(jet); colorbar;

%% 廲幉傪懳悢昞帵
figure;surf(log(abs(Fs))); shading interp; axis ij;xlabel('X');ylabel('Y');

%% 廔椆









%% 廲僛僽儔僷僞乕儞
I = [ones(256,2), zeros(256,2)];  % 墶曽岦4僺僋僙儖廃婜僷僞乕儞
I1 = repmat(I,[1,64]);            % 256x256 僺僋僙儖偺夋憸
imtool(I1);
F1 = fft2(I1);
Fs1 = fftshift(F1);
figure;surf(abs(Fs1)); shading interp; axis ij;xlabel('X');ylabel('Y');

%% 廲僛僽儔僷僞乕儞 (旕2偺奒忔僒僀僘)
I2 = repmat(I,[1,20]);            % 256x80 僺僋僙儖偺夋憸
imtool(I2);
F2 = fft2(I2);
Fs2 = fftshift(F2);
figure;surf(abs(Fs2)); shading interp; axis ij;xlabel('X');ylabel('Y');

%% 廲僛僽儔僷僞乕儞 (旕2偺奒忔僒僀僘丗FFT帪偵2偺奒忔傊)
F3 = fft2(I2, 256, 256);      % 夋憸僨乕僞傪0杽傔偱攝楍僒僀僘傪戝偒偔偟丄256x256偺寢壥傪惗惉
Fs3 = fftshift(F3);
figure;surf(abs(Fs3)); shading interp; axis ij;xlabel('X');ylabel('Y');

%% 廲僛僽儔僷僞乕儞 (旕2偺奒忔僒僀僘丗庤摦偱2偺奒忔僒僀僘傊曄峏)
I3 = [I2, zeros(256,176)];
imtool(I3);
F3 = fft2(I3);
Fs3 = fftshift(F3);
figure;surf(abs(Fs3)); shading interp; axis ij;xlabel('X');ylabel('Y');

%%
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