PCA检测人脸的简单示例_matlab实现

%训练
%Lx=X'*X
clear;
clc;
train_path='..\Data\TrainingSet\';
phi=zeros(64*64,20);
for i=1:20
path=strcat(train_path,num2str(i),'.bmp');
Image=imread(path);
Image=imresize(Image,[64,64]);
phi(:,i)=double(reshape(Image,1,[])');
end;
%mean
mean_phi=mean(phi,2);
mean_face=reshape(mean_phi,64,64);
Image_mean=mat2gray(mean_face);
imwrite(Image_mean,'meanface.bmp','bmp');
%demean
for i=1:19
X(:,i)=phi(:,i)-mean_phi;
end
Lx=X'*X;
tic;
[eigenvector,eigenvalue]=eigs(Lx,19);
toc;
%normalization
for i=1:19
%K-L变换
UL(:,i)=X*eigenvector(:,i)/sqrt(eigenvalue(i,i));
end
%display Eigenface
for i=1:19
Eigenface=reshape(UL(:,i),[64,64]);
figure(i);
imshow(mat2gray(Eigenface));
end

得到的均值图像mean_face：