www.gusucode.com > 有关虹膜特征提取的部分很有借鉴意义源码程序 > iris recognition.txt
function iris(filename);
im=(rgb2gray(imread(filename)));
im=im(13:288, 1:342);
j=double(im);
[d1 d2]=size(j);
f=0;
%stand out iris-pupil by contrasting
LOW=3;
HIGH=175;
for loop=1:2:LOW*2
for loop1=1:d1
for loop2=1:d2
if j(loop1,loop2)<LOW+loop
j(loop1,loop2)=0;
elseif j(loop1,loop2)>HIGH-loop
j(loop1,loop2)=255;
else
j(loop1,loop2)=round(j(loop1,loop2)/(HIGH-LOW-
2*loop)*255);
end
end
end
end
% filter bright pixels by using threshold brightness
threshold=200;
%f=f+1; figure(f), imshow(j), imagesc(j);
29 Appendix B
pupil= (j < threshold);
%f=f+1; figure(f), imshow(pupil), imagesc(pupil);
%filtering using area of a whole circle
diameter=33;
mid=(diameter+1)/2;
bound=mid-1;
con=7;
dif=(con+1)/2-1;
result=zeros(d1-mid, d2-mid);
circle=imcircle(diameter);
replace=imcircle(con);
area=(diameter/2)^2*pi;
for loop1 = 1 : d1
for loop2 = 1 : d2
if (loop1<mid | loop1>d1-mid | loop2<mid | loop2>d2-mid)
result(loop1,loop2)=0;
else
acc=0;
compare=pupil(loop1-bound : loop1+bound, loop2-bound :
loop2+bound);
prod = circle.*compare;
acc=sum(sum(prod));
if acc / area > 0.85
result(loop1-dif: loop1+dif, loop2-dif: loop2+dif) =
ones(con,con);
else
result(loop1,loop2)=0;
end
end
end
end
iris=result;
[d1 d2]=size(iris);
%approximate center using weight centroid of pixels
column_weights = [1:d2] .* sum(iris);
column_centroid = round(sum(column_weights(:)) / sum(iris(:)));
row_weights = [1:d1] .* sum(iris, 2)';
row_centroid = round(sum(row_weights(:)) / sum(iris(:)));
f=f+1; figure(f), imshow(im),imagesc(im);pixval;
%line([column_centroid, column_centroid], [1, d1]);
%line([1, d2], [row_centroid, row_centroid]);
%darken pupil
im2=im;
for loop=1:5
im2=histeq(im2);
for loop1=1:d1
for loop2=1:d2
if im2(loop1,loop2)<50+loop*10
im2(loop1,loop2)=0;
elseif im2(loop1,loop2)>160-loop*10
im2(loop1,loop2)=255;
end
end
end
end
30 Appendix B
%find boundary of pupil using sudden change in sum of brightness of
concentric circles
im2=double(im2);
pupilbound=73;
centers=0;
dev=2;
pupilser=zeros((dev*2+1)^2, (pupilbound+1)/2);
for loop1=-dev:dev
for loop2=-dev:dev
centers=centers+1;
for loop3=1:2:pupilbound
circle=double(bwperim(imcircle(loop3)));
pupilser(centers,(loop3+1)/2) =
sum(sum(im2(row_centroid+loop1-(loop3-1)/2:row_centroid+loop1+(loop3-
1)/2 , column_centroid+loop2-(loop3-
1)/2:column_centroid+loop2+(loop3-
1)/2).*circle))/sum(sum(circle))*128;
end
end
end
pupilser=pupilser';
inner=zeros((pupilbound+1)/2, (dev*2+1)^2);
for loop1=1 : (dev*2+1)^2
check=0;
radius=-1;
for loop2=1 : (pupilbound+1)/2
radius=radius+1;
check=check+pupilser(loop2,loop1);
if check > 0
inner(loop2,loop1)=check;
inner(loop2+1:(pupilbound+1)/2,loop1)=0;
% inner(2,loop1)=radius;
break;
end
end
end
[a1,b1]=max(inner); %a1=max of gradient in each test center, b1 is
the correspond radius
[a2,b2]=max(a1); %a2=max of all the gradients so b2 = correspoding
test center
pupilcenter=b2;
pupilradius=b1(b2); %b2 is the center and b1(b2) is the center's
radius
pupilcenter_x=column_centroid+(-(dev+1)+rem(pupilcenter,dev*2+1));
pupilcenter_y=row_centroid+-((dev+1)-((pupilcenter -
rem(pupilcenter,dev*2+1)) / (dev*2+1)+1));
hold on; o=0:.01:2*pi; plot(pupilradius*cos(o)+pupilcenter_x,
pupilradius*sin(o)+pupilcenter_y);
ph=line([pupilcenter_x, pupilcenter_x], [pupilcenter_y -10,
pupilcenter_y+10]);
pv=line([pupilcenter_x-10, pupilcenter_x+10], [pupilcenter_y,
pupilcenter_y]);
hold off;
f=f+1; figure(f); plot((pupilser));
%find iris boundary
%darken iris
im2=im;
31 Appendix B
for loop=1:5
im2=histeq(im2);
for loop1=1:d1
for loop2=1:d2
if im2(loop1,loop2)<60+loop*10
im2(loop1,loop2)=0;
elseif im2(loop1,loop2)>170-loop*10
im2(loop1,loop2)=255;
end
end
end
end
im2=double(im2);
irisbound=163;
centers=0;
dev=2;
irisser=zeros((dev*2+1)^2, (irisbound+1)/2);
for loop1=-dev:dev
for loop2=-dev:dev
counter=(pupilbound+1)/2-1;
centers=centers+1;
jump=0;
for loop3=pupilbound:2:irisbound
counter=counter+1;
jump=jump+2;
circle=double(bwperim(imcircle(loop3)));
circle(1:(loop3+1)/2-(pupilbound+1)/2, :)=0;
circle((loop3+1)/2+(pupilbound+1)/2:loop3, :)=0;
irisser(centers,counter) = sum(sum(im2(pupilcenter_y+loop1 -
((loop3+1)/2-1):pupilcenter_y+loop1+((loop3+1)/2-1) ,
pupilcenter_x+loop2-((loop3+1)/2-1) :
pupilcenter_x+loop2+((loop3+1)/2-1)).*circle))/sum(sum(circle))*128;
end
end
end
irisser=irisser';
irisgrad=gradient(irisser');
irisgrad=irisgrad';
[g1,g2]=size(irisgrad);
for loop1=g1
for loop2=g2
if irisgrad(loop1,loop2)<0
irisgrad(loop1,loop2)=0;
end
end
end
[i1,j1]=max(irisgrad); %i1=max of gradient in each test center, j1 is
the correspond radius
[i2,j2]=max(i1); %i2=max of all the gradients so j2 = correspoding
test center
iriscenter=j2;
irisradius=j1(j2);
iriscenter_x=pupilcenter_x+(-(dev+1)+rem(iriscenter,dev*2+1));
iriscenter_y=pupilcenter_y+-((dev+1)-((iriscenter -
rem(iriscenter,dev*2+1)) / (dev*2+1)+1));
32 Appendix B
figure(1); hold on; o=0:.01:2*pi;
plot(irisradius*cos(o)+iriscenter_x,
irisradius*sin(o)+iriscenter_y,'r');
ih=line([iriscenter_x-20, iriscenter_x+20], [iriscenter_y+20,
iriscenter_y-20]);
iv=line([iriscenter_x-20, iriscenter_x+20], [iriscenter_y-20,
iriscenter_y+20]);
set(ih,'color',[1 0 0]); set(iv,'color',[1 0 0]);
l1=line([pupilcenter_x, iriscenter_x], [pupilcenter_y+pupilradius,
iriscenter_y+irisradius]);
l2=line([pupilcenter_x+pupilradius, iriscenter_x+irisradius],
[pupilcenter_y, iriscenter_y]);
l3=line([pupilcenter_x, iriscenter_x], [pupilcenter_y -pupilradius,
iriscenter_y-irisradius]);
l4=line([pupilcenter_x-pupilradius, iriscenter_x-irisradius],
[pupilcenter_y, iriscenter_y]);
set(l1,'color',[1 1 0]); set(l2,'color',[1 1 0]);set(l3,'color',[1 1
0]); set(l4, 'color',[1 1 0]);
line;
hold off;