Activity 13: Photometric Stereo

In this activity we are to reconstruct an image using different images taken from the same point with different point source locations. The following are the images used with their corresponding point source positions



Using the following formula, we were able to obtain a 3d plot for the original image

loadmatfile("Photos.mat");
scf(0);imshow(I1,[]);
scf(1);imshow(I2,[]);
scf(2);imshow(I3,[]);
scf(3);imshow(I4,[]);
V1 = [0.085832, 0.17365, 0.98106];
V2 = [0.085832, -0.17365, 0.98106];
V3 = [0.17365, 0, 0.98481];
V4 = [0.16318, -0.34202, 0.92542];

I(1,:) = I1(:)';
I(2,:) = I2(:)';
I(3,:) = I3(:)';
I(4,:) = I4(:)';
//I = cat(1,I1(:)',I2(:)',I3(:)',I4(:)');
V = cat(1,V1,V2,V3,V4);

g = inv(V'*V)*V'*I;
N = size(g);

for i = 1:N(2)
gMag(i) = sqrt(g(1,i)**2+g(2,i)**2+g(3,i)**2+0.0000000000001);
end

nh(1,:) = (g(1,:)./gMag');
nh(2,:) = (g(2,:)./gMag');
nh(3,:) = (g(3,:)./gMag')+0.0000000000001;

fx = -nh(1,:)./nh(3,:);
fx = matrix(fx,[128,128])
fy = -nh(2,:)./nh(3,:);
fy = matrix(fy,[128,128]);
f = cumsum(fx,2)+cumsum(fy,1);

plot3d(1:128,1:128,f);


I will grade myself 10 for this activity since I was able to meet the objectives.
Collaborator: Eduardo David