click_ima_calib.m

% Cleaned-up version of init_calib.m

fprintf(1,'\nProcessing image %d...\n',kk);

eval(['I = I_' num2str(kk) ';']);

if exist(['wintx_' num2str(kk)]),
    
    eval(['wintxkk = wintx_' num2str(kk) ';']);
    
    if ~isempty(wintxkk) & ~isnan(wintxkk),
        
        eval(['wintx = wintx_' num2str(kk) ';']);
        eval(['winty = winty_' num2str(kk) ';']);
        
    end;
end;


fprintf(1,'Using (wintx,winty)=(%d,%d) - Window size = %dx%d      (Note: To reset the window size, run script clearwin)\n',wintx,winty,2*wintx+1,2*winty+1);
%fprintf(1,'Note: To reset the window size, clear wintx and winty and run ''Extract grid corners'' again\n');


figure(2);
image(I);
colormap(map);
set(2,'color',[1 1 1]);

title(['Click on the four extreme corners of the rectangular pattern (first corner = origin)... Image ' num2str(kk)]);

disp('Click on the four extreme corners of the rectangular complete pattern (the first clicked corner is the origin)...');

x= [];y = [];
figure(2); hold on;
for count = 1:4,
    [xi,yi] = ginput4(1);
    [xxi] = cornerfinder([xi;yi],I,winty,wintx);
    xi = xxi(1);
    yi = xxi(2);
    figure(2);
    plot(xi,yi,'+','color',[ 1.000 0.314 0.510 ],'linewidth',2);
    plot(xi + [wintx+.5 -(wintx+.5) -(wintx+.5) wintx+.5 wintx+.5],yi + [winty+.5 winty+.5 -(winty+.5) -(winty+.5)  winty+.5],'-','color',[ 1.000 0.314 0.510 ],'linewidth',2);
    x = [x;xi];
    y = [y;yi];
    plot(x,y,'-','color',[ 1.000 0.314 0.510 ],'linewidth',2);
    drawnow;
end;
plot([x;x(1)],[y;y(1)],'-','color',[ 1.000 0.314 0.510 ],'linewidth',2);
drawnow;
hold off;


%[x,y] = ginput4(4);

[Xc,good,bad,type] = cornerfinder([x';y'],I,winty,wintx); % the four corners

x = Xc(1,:)';
y = Xc(2,:)';


% Sort the corners:
x_mean = mean(x);
y_mean = mean(y);
x_v = x - x_mean;
y_v = y - y_mean;

theta = atan2(-y_v,x_v);
[junk,ind] = sort(theta);

[junk,ind] = sort(mod(theta-theta(1),2*pi));

%ind = ind([2 3 4 1]);

ind = ind([4 3 2 1]); %-> New: the Z axis is pointing uppward

x = x(ind);
y = y(ind);
x1= x(1); x2 = x(2); x3 = x(3); x4 = x(4);
y1= y(1); y2 = y(2); y3 = y(3); y4 = y(4);


% Find center:
p_center = cross(cross([x1;y1;1],[x3;y3;1]),cross([x2;y2;1],[x4;y4;1]));
x5 = p_center(1)/p_center(3);
y5 = p_center(2)/p_center(3);

% center on the X axis:
x6 = (x3 + x4)/2;
y6 = (y3 + y4)/2;

% center on the Y axis:
x7 = (x1 + x4)/2;
y7 = (y1 + y4)/2;

% Direction of displacement for the X axis:
vX = [x6-x5;y6-y5];
vX = vX / norm(vX);

% Direction of displacement for the X axis:
vY = [x7-x5;y7-y5];
vY = vY / norm(vY);

% Direction of diagonal:
vO = [x4 - x5; y4 - y5];
vO = vO / norm(vO);

delta = 30;


figure(2); 
image(I);
colormap(map);
hold on;
plot([x;x(1)],[y;y(1)],'g-');
plot(x,y,'og');
hx=text(x6 + delta * vX(1) ,y6 + delta*vX(2),'X');
set(hx,'color','g','Fontsize',14);
hy=text(x7 + delta*vY(1), y7 + delta*vY(2),'Y');
set(hy,'color','g','Fontsize',14);
hO=text(x4 + delta * vO(1) ,y4 + delta*vO(2),'O','color','g','Fontsize',14);
hold off;


if manual_squares,
    
    n_sq_x = input(['Number of squares along the X direction ([]=' num2str(n_sq_x_default) ') = ']); %6
    if isempty(n_sq_x), n_sq_x = n_sq_x_default; end;
    n_sq_y = input(['Number of squares along the Y direction ([]=' num2str(n_sq_y_default) ') = ']); %6
    if isempty(n_sq_y), n_sq_y = n_sq_y_default; end; 
    
else
    
    % Try to automatically count the number of squares in the grid
    
    n_sq_x1 = count_squares(I,x1,y1,x2,y2,wintx);
    n_sq_x2 = count_squares(I,x3,y3,x4,y4,wintx);
    n_sq_y1 = count_squares(I,x2,y2,x3,y3,wintx);
    n_sq_y2 = count_squares(I,x4,y4,x1,y1,wintx);
    
    
    
    % If could not count the number of squares, enter manually
    
    if (n_sq_x1~=n_sq_x2)|(n_sq_y1~=n_sq_y2),
        
        
        disp('Could not count the number of squares in the grid. Enter manually.');
        n_sq_x = input(['Number of squares along the X direction ([]=' num2str(n_sq_x_default) ') = ']); %6
        if isempty(n_sq_x), n_sq_x = n_sq_x_default; end;
        n_sq_y = input(['Number of squares along the Y direction ([]=' num2str(n_sq_y_default) ') = ']); %6
        if isempty(n_sq_y), n_sq_y = n_sq_y_default; end; 
        
    else
        
        n_sq_x = n_sq_x1;
        n_sq_y = n_sq_y1;
        
    end;
    
end;


n_sq_x_default = n_sq_x;
n_sq_y_default = n_sq_y;


if (exist('dX')~=1)|(exist('dY')~=1), % This question is now asked only once
    % Enter the size of each square
    
    dX = input(['Size dX of each square along the X direction ([]=' num2str(dX_default) 'mm) = ']);
    dY = input(['Size dY of each square along the Y direction ([]=' num2str(dY_default) 'mm) = ']);
    if isempty(dX), dX = dX_default; else dX_default = dX; end;
    if isempty(dY), dY = dY_default; else dY_default = dY; end;
    
else
    
    fprintf(1,['Size of each square along the X direction: dX=' num2str(dX) 'mm\n']);
    fprintf(1,['Size of each square along the Y direction: dY=' num2str(dY) 'mm   (Note: To reset the size of the squares, clear the variables dX and dY)\n']);
    %fprintf(1,'Note: To reset the size of the squares, clear the variables dX and dY\n');
    
end;


% Compute the inside points through computation of the planar homography (collineation)

a00 = [x(1);y(1);1];
a10 = [x(2);y(2);1];
a11 = [x(3);y(3);1];
a01 = [x(4);y(4);1];


% Compute the planar collineation: (return the normalization matrix as well)

[Homo,Hnorm,inv_Hnorm] = compute_homography([a00 a10 a11 a01],[0 1 1 0;0 0 1 1;1 1 1 1]);


% Build the grid using the planar collineation:

x_l = ((0:n_sq_x)'*ones(1,n_sq_y+1))/n_sq_x;
y_l = (ones(n_sq_x+1,1)*(0:n_sq_y))/n_sq_y;
pts = [x_l(:) y_l(:) ones((n_sq_x+1)*(n_sq_y+1),1)]';

XX = Homo*pts;
XX = XX(1:2,:) ./ (ones(2,1)*XX(3,:));


% Complete size of the rectangle

W = n_sq_x*dX;
L = n_sq_y*dY;




%%%%%%%%%%%%%%%%%%%%%%%% ADDITIONAL STUFF IN THE CASE OF HIGHLY DISTORTED IMAGES %%%%%%%%%%%%%
figure(2);
hold on;
plot(XX(1,:),XX(2,:),'r+');
title('The red crosses should be close to the image corners');
hold off;

disp('If the guessed grid corners (red crosses on the image) are not close to the actual corners,');
disp('it is necessary to enter an initial guess for the radial distortion factor kc (useful for subpixel detection)');
quest_distort = input('Need of an initial guess for distortion? ([]=no, other=yes) ');

quest_distort = ~isempty(quest_distort);

if quest_distort,
    % Estimation of focal length:
    c_g = [size(I,2);size(I,1)]/2 + .5;
    f_g = Distor2Calib(0,[[x(1) x(2) x(4) x(3)] - c_g(1);[y(1) y(2) y(4) y(3)] - c_g(2)],1,1,4,W,L,[-W/2 W/2 W/2 -W/2;L/2 L/2 -L/2 -L/2; 0 0 0 0],100,1,1);
    f_g = mean(f_g);
    script_fit_distortion;
end;
%%%%%%%%%%%%%%%%%%%%% END ADDITIONAL STUFF IN THE CASE OF HIGHLY DISTORTED IMAGES %%%%%%%%%%%%%





Np = (n_sq_x+1)*(n_sq_y+1);

disp('Corner extraction...');

grid_pts = cornerfinder(XX,I,winty,wintx); %%% Finds the exact corners at every points!



%save all_corners x y grid_pts

grid_pts = grid_pts - 1; % subtract 1 to bring the origin to (0,0) instead of (1,1) in matlab (not necessary in C)



ind_corners = [1 n_sq_x+1 (n_sq_x+1)*n_sq_y+1 (n_sq_x+1)*(n_sq_y+1)]; % index of the 4 corners
ind_orig = (n_sq_x+1)*n_sq_y + 1;
xorig = grid_pts(1,ind_orig);
yorig = grid_pts(2,ind_orig);
dxpos = mean([grid_pts(:,ind_orig) grid_pts(:,ind_orig+1)]');
dypos = mean([grid_pts(:,ind_orig) grid_pts(:,ind_orig-n_sq_x-1)]');


x_box_kk = [grid_pts(1,:)-(wintx+.5);grid_pts(1,:)+(wintx+.5);grid_pts(1,:)+(wintx+.5);grid_pts(1,:)-(wintx+.5);grid_pts(1,:)-(wintx+.5)];
y_box_kk = [grid_pts(2,:)-(winty+.5);grid_pts(2,:)-(winty+.5);grid_pts(2,:)+(winty+.5);grid_pts(2,:)+(winty+.5);grid_pts(2,:)-(winty+.5)];


figure(3);
image(I); colormap(map); hold on;
plot(grid_pts(1,:)+1,grid_pts(2,:)+1,'r+');
plot(x_box_kk+1,y_box_kk+1,'-b');
plot(grid_pts(1,ind_corners)+1,grid_pts(2,ind_corners)+1,'mo');
plot(xorig+1,yorig+1,'*m');
h = text(xorig+delta*vO(1),yorig+delta*vO(2),'O');
set(h,'Color','m','FontSize',14);
h2 = text(dxpos(1)+delta*vX(1),dxpos(2)+delta*vX(2),'dX');
set(h2,'Color','g','FontSize',14);
h3 = text(dypos(1)+delta*vY(1),dypos(2)+delta*vY(2),'dY');
set(h3,'Color','g','FontSize',14);
xlabel('Xc (in camera frame)');
ylabel('Yc (in camera frame)');
title('Extracted corners');
zoom on;
drawnow;
hold off;


Xi = reshape(([0:n_sq_x]*dX)'*ones(1,n_sq_y+1),Np,1)';
Yi = reshape(ones(n_sq_x+1,1)*[n_sq_y:-1:0]*dY,Np,1)';
Zi = zeros(1,Np);

Xgrid = [Xi;Yi;Zi];


% All the point coordinates (on the image, and in 3D) - for global optimization:

x = grid_pts;
X = Xgrid;


% Saves all the data into variables:

eval(['dX_' num2str(kk) ' = dX;']);
eval(['dY_' num2str(kk) ' = dY;']);  

eval(['wintx_' num2str(kk) ' = wintx;']);
eval(['winty_' num2str(kk) ' = winty;']);

eval(['x_' num2str(kk) ' = x;']);
eval(['X_' num2str(kk) ' = X;']);

eval(['n_sq_x_' num2str(kk) ' = n_sq_x;']);
eval(['n_sq_y_' num2str(kk) ' = n_sq_y;']);