--- Saving session to: ECE480.PH437_21-Jan-2002.txt --- Processed startup.m --- doc ; ; ; ; ; ; ; f=[1 1 1 1 0 0 0 0] f = Columns 1 through 7 1 1 1 1 0 0 0 Column 8 0 stem(f) fft(f) ans = Columns 1 through 2 4.0000 1.0000 - 2.4142i Columns 3 through 4 0 1.0000 - 0.4142i Columns 5 through 6 0 1.0000 + 0.4142i Columns 7 through 8 0 1.0000 + 2.4142i fft(f)' ans = 4.0000 1.0000 + 2.4142i 0 1.0000 + 0.4142i 0 1.0000 - 0.4142i 0 1.0000 - 2.4142i (fft(f)')/8 ans = 0.5000 0.1250 + 0.3018i 0 0.1250 + 0.0518i 0 0.1250 - 0.0518i 0 0.1250 - 0.3018i dftsep Press a key, any key... Waiting for keypress... Done! type dftsep % EE437 Intro to Image Processing, S96 % Day 18: Separability property: 2-D DFT from two % passes with 1-D DFT % updated Winter 2001-02 % Image size (square image) n=64; % Pulse width w=10; % f(x,y): Square pulse at center of image fxy = zeros(n); fxy((n/2)-(w/2):(n/2)+(w/2),(n/2)-(w/2):(n/2)+(w/2)) =... ones(w+1); f1=figure(1); bigfig mesh(fxy) axis('ij') bigtitle('f(x,y)'); xlabel('x'); ylabel('y') disp('Press a key, any key...') pause % F(u,y): 1-D DFT along the x direction Fuy = fxy; for y=1:n, Fuy(y,:)=fft(fxy(y,:)); end f2=figure(2); bigfig mesh(abs(Fuy)) axis('ij') bigtitle('|F(u,y)|'); xlabel('u'); ylabel('y') disp('Waiting for keypress...') pause % F(u,v): 1-D DFT along the y direction using F(u,y) % as the input image. Fuv = Fuy; for u=1:n, Fuv(:,u)=fft(Fuy(:,u)); end f3=figure(3); bigfig mesh(abs(Fuv)) axis('ij') bigtitle('|F(u,v)|'); xlabel('u'); ylabel('v') disp('Done!') exit