a b/combinedDeepLearningActiveContour/dim_reduction.m
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% dimension reduction using PCA
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clc
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clear all
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close all
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addpath('functions')
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%%
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load matFiles/training_data; 
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% total images
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I=t_Iroi;
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[x,y,z]=size(I);
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I1=reshape(I,x*y,z);
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% apply PCA
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N=size(I1,1);
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C=I1*I1'/N;
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[U,S,V]=svd(C);
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% reduce dimension
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n=90;
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I2=I1'*U(:,1:n);
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%save pca_results
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%% recover
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I3=I2*U(:,1:n)';
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I4=I3';
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I5=reshape(I4,x,y,z);
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imagesc(I5(:,:,1));colormap(gray)
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% total ROI
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B=t_yROI;
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[x,y,z]=size(B);
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B1=reshape(B,x*y,z);
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p2=pca(B1');
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B2=B1'*p2;
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% recover
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B3=B2*p2';
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B4=B3';
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B5=reshape(B4,x,y,z);
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figure
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imagesc(B5(:,:,2));colormap(gray)
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imagesc(B(:,:,2));colormap(gray)
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Br=imresize(B(:,:,2),40/256);
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Brr=imresize(Br,256/40);
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Brr=round(Brr);
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imagesc(Brr);colormap(gray)
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