pca.zip_PCA图像_图像主成分_图像识别

% function?FaceRecognition?? clear %?calc?xmean,sigma?and?its?eigen?decomposition???? close all allsamples=[];%所有训练图像??? for i=1:1 for?j=1:1?????????? ????????if(i<10)?? % ???????????a=imread(strcat('E:\ORL_92x112\00',num2str(i),'0',num2str(j),'.bmp'));??????? a=imread('D:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\VCWizards\AppWiz\MFC\Application\templates\1042\buttons.bmp');?? ????????else?? ????????????a=imread(strcat('E:\ORL_92x112\0',num2str(i),'0',num2str(j),'.bmp'));???? ????????end???????????? ????????b=a(1:112*92);?%?b是行矢量?1×N，其中N＝10304，提取顺序是先列后行，即从上到下，从左到右?????????? ????????b=double(b);?????????? ????????allsamples=[allsamples;?b];??%?allsamples?是一个M?*?N?矩阵，allsamples?中每一行数据代表一张图片，其中M＝200????? ????end?? end?? samplemean=mean(allsamples);?%?平均图片，1?×?N???? figure%平均图?? imshow(mat2gray(reshape(samplemean,112,92)));?? for?i=1:200??? ????xmean(i,:)=allsamples(i,:)-samplemean;?%?xmean是一个M?×?N矩阵，xmean每一行保存的数据是“每个图片数据-平均图片”??? end;????? %?figure%平均图?? %?imshow(mat2gray(reshape(xmean(1,:),112,92)));?? sigma=xmean*xmean';???%?M?*?M?阶矩阵??? [v,d]=eig(sigma);?? d1=diag(d);??? [d2,index]=sort(d1);?%以升序排序??? cols=size(v,2);%?特征向量矩阵的列数?? ?? for?i=1:cols???????? ????vsort(:,i)?=?v(:,?index(cols-i+1)?);?%?vsort?是一个M*col(注:col一般等于M)阶矩阵，保存的是按降序排列的特征向量,每一列构成一个特征向量???????? ????dsort(i)???=?d1(?index(cols-i+1)?);??%?dsort?保存的是按降序排列的特征值，是一维行向量??? end??%完成降序排列?%以下选择90%的能量??? dsum?=?sum(dsort);??????? dsum_extract?=?0;????? p?=?0;??????? while(?dsum_extract/dsum?<?0.9)????????? ????p?=?p?+?1;???????????? ????dsum_extract?=?sum(dsort(1:p));??????? end?? a=1:1:200;?? for?i=1:1:200?? y(i)=sum(dsort(a(1:i))?);?? end?? figure?? y1=ones(1,200);?? plot(a,y/dsum,a,y1*0.9,'linewidth',2);?? grid?? title('前n个特征特占总的能量百分比');?? xlabel('前n个特征值');?? ylabel('占百分比');?? figure?? plot(a,dsort/dsum,'linewidth',2);?? grid?? title('第n个特征特占总的能量百分比');?? xlabel('第n个特征值');?? ylabel('占百分比');?? i=1;??%?(训练阶段)计算特征脸形成的坐标系?? while?(i<=p?&&?dsort(i)>0)???????? ????base(:,i)?=?dsort(i)^(-1/2)?*?xmean'?*?vsort(:,i);???%?base是N×p阶矩阵，除以dsort(i)^(1/2)是对人脸图像的标准化，特征脸?? ??????i?=?i?+?1;??? end???%?add?by?wolfsky?就是下面两行代码，将训练样本对坐标系上进行投影,得到一个?M*p?阶矩阵allcoor???? %??? %?for?i=1:20?? %???figure%平均图?? %?b=reshape(base(:,i)',112,92);%?? %?imshow(mat2gray(b));?? %?end?? ?? allcoor?=?allsamples?*?base;?accu?=?0;???%?测试过程?? ?? for?i=1:40??????? ????for?j=6:10?%读入40?x?5?副测试图像??????????? ?????????if(i<10)?? ????????????if(j<10)?? ?????????????a=imread(strcat('E:\ORL_92x112\00',num2str(i),'0',num2str(j),'.bmp'));??????? ????????????else?? ?????????????a=imread(strcat('E:\ORL_92x112\00',num2str(i),num2str(j),'.bmp'));??????? ????????????end?? ?????????else?? ?????????????if(j<10)?? ?????????????a=imread(strcat('E:\ORL_92x112\0',num2str(i),'0',num2str(j),'.bmp'));??????? ????????????else?? ?????????????a=imread(strcat('E:\ORL_92x112\0',num2str(i),num2str(j),'.bmp'));??????? ?????????????end?? ????????end???????? ????????b=a(1:10304);?????????? ????????b=double(b);?????????? ????????tcoor=?b?*?base;?%计算坐标，是1×p阶矩阵???????? ????????for?k=1:200??????????????????? ????????????mdist(k)=norm(tcoor-allcoor(k,:));?????????? ????????end;??????????%三阶近邻????? ????????[dist,index2]=sort(mdist);???????????? ????????class1=floor(?index2(1)/5?)+1;???????? ????????class2=floor(index2(2)/5)+1;?????????? ????????class3=floor(index2(3)/5)+1;?????????? ????????if?class1~=class2?&&?class2~=class3??? ????????????class=class1;??????????? ????????elseif?class1==class2???????????? ????????????class=class1;??????????? ????????elseif?class2==class3??????? ????????????class=class2;??????????? ????????end;??????????? ????????if?class==i???????? ????????????accu=accu+1;?????????? ????????end;????? ????end;?? end;???? accuracy=accu/200?%输出识别率??