傅里叶光学常用函数matlab程序

 Phase Images body { background-color: white; margin:10px; } h1 { color: #990000; font-size: x-large; } h2 { color: #990000; font-size: medium; } /* Make the text shrink to fit narrow windows, but not stretch too far in wide windows. */ p,h1,h2,div.content div { max-width: 600px; /* Hack for IE6 */ width: auto !important; width: 600px; } pre.codeinput { background: #EEEEEE; padding: 10px; } @media print { pre.codeinput {word-wrap:break-word; width:100%;} } span.keyword {color: #0000FF} span.comment {color: #228B22} span.string {color: #A020F0} span.untermstring {color: #B20000} span.syscmd {color: #B28C00} pre.codeoutput { color: #666666; padding: 10px; } pre.error { color: red; } p.footer { text-align: right; font-size: xx-small; font-weight: lighter; font-style: italic; color: gray; } Phase Images Contents embed phase image inverse transform (no filter) dark-field schlieren method positive phase contrast negative phase contrast img = imread('Zernike.jpg'); imshow(img); embed phase image g1 = rgb2gray(im2double(img)); g2 = fftprep(g1); mk = 0.1; %% phase modulation g = exp(j*2*pi*mk*g2); gshift = fftshift(g); g_fft = fft2(gshift); gf = fftshift(g_fft); out = gf.*conj(gf); gmax = max(max(out)); gmin = min(min(out)); fprintf('maximum %g minimum %g\n',gmax,gmin); logim(out/gmax,8); clear gf; maximum 4.06996e+009 minimum 0.000164659 inverse transform (no filter) gt = fftshift(sqrt(g2)); gf = fft2(gt); gs = ifft2(gf); ginv = fftshift(gs); out = ginv.*conj(ginv); gmax = max(max(out)); gmin = min(min(out)); fprintf('maximum %g minimum %g\n',gmax,gmin); imshow(out/gmax); clear gt gf gs ginv maximum 1 minimum 0 dark-field gfilt = g_fft; gfilt(1,1) = 0.0; gs = ifft2(gfilt); ginv = fftshift(gs); out = ginv.*conj(ginv); gmax = max(max(out)); gmin = min(min(out)); fprintf('maximum %g minimum %g\n',gmax,gmin); imshow(out/gmax); maximum 0.179064 minimum 0.000704727 schlieren method sz = size(g_fft); N = max(sz); gfilt = g_fft; gfilt(N/2:N,1:N) = 0.0; gs = ifft2(gfilt); ginv = fftshift(gs); out = ginv.*conj(ginv); gmax = max(max(out)); gmin = min(min(out)); fprintf('maximum %g minimum %g\n',gmax,gmin); imshow(out/gmax); maximum 2.27131 minimum 0.302775 positive phase contrast gfilt = g_fft; gfilt(1,1) = g_fft(1,1)*(0.5j*pi); gs = ifft2(gfilt); ginv = fftshift(gs); out = ginv.*conj(ginv); gmax = max(max(out)); gmin = min(min(out)); fprintf('maximum %g minimum %g\n',gmax,gmin); imshow(out/gmax); maximum 3.79592 minimum 1.77809 negative phase contrast gfilt = g_fft; gfilt(1,1) = g_fft(1,1)*(1.5j*pi); gs = ifft2(gfilt); ginv = fftshift(gs); out = ginv.*conj(ginv); gmax = max(max(out)); gmin = min(min(out)); fprintf('maximum %g minimum %g\n',gmax,gmin); imshow(out/gmax); maximum 25.0585 minimum 19.2864 imshow((out-gmin)/(gmax-gmin)); Published with MATLAB® 7.6