自适应阈值分割的源程序

function f_threshold(file_name) % Evan Ruzanski and Chiou-Wei Tsai % UCSB, 11/3/2003 clc % Initialize variables thresh = 77; gray_range = 256; % Read and display test image as given in Lee, p. 712 im = imread(file_name); figure imshow(im); title('Original 2D image'); % Perform binary spatial lifting s = size(im); imz(1:s(1),1:s(2),1:gray_range) = 0; im = double(im); % Typecast for arithmetic operations for i = 1:s(1) for j = 1:s(2) if im(i,j) > 1 imz(i,j,1:im(i,j)) = 1; % Make 3rd Dim binary end end end % 3D representation of lifting the image figure(2) x = 1:s(1); y = 1:s(2); [X,Y] = meshgrid(x,y); colormap(gray) rotate3d mesh(X,Y,im); axis tight title('Lifted representation of 2D image') % Take 3D FFT of binary lifted data IMZT = fftn(imz); % Slice and extract S = size(IMZT); un = [zeros(1,thresh - 1) ones(1,S(3) - (thresh - 1))]; % Create unit step U = fft(un); for i = 1:S(1), for j = 1: S(2), IM2D(i, j) = IMZT(i,j,:)*U'; end end % Recover and disply 2D image im2d = ifft2(IM2D); im2d = 1/256*fix(real(im2d)); figure imshow(uint8(im2d)); title('Thresholded image');