Contents

extrinsic_computation

% INPUT THE IMAGE FILE NAME:

if ~exist('fc','var')||~exist('cc','var')||~exist('kc','var')||~exist('alpha_c','var'),
   fprintf(1,'No intrinsic camera parameters available.\n');
   return;
end;

dir;

fprintf(1,'\n');
disp('Computation of the extrinsic parameters from an image of a pattern');
disp('The intrinsic camera parameters are assumed to be known (previously computed)');

fprintf(1,'\n');
image_name = input('Image name (full name without extension): ','s');

format_image2 = '0';

while format_image2 == '0',

   format_image2 =  input('Image format: ([]=''r''=''ras'', ''b''=''bmp'', ''t''=''tif'', ''p''=''pgm'', ''j''=''jpg'', ''m''=''ppm'') ','s');

	if isempty(format_image2),
   	format_image2 = 'ras';
	end;

   if lower(format_image2(1)) == 'm',
      format_image2 = 'ppm';
   else
      if lower(format_image2(1)) == 'b',
         format_image2 = 'bmp';
      else
         if lower(format_image2(1)) == 't',
            format_image2 = 'tif';
         else
            if lower(format_image2(1)) == 'p',
               format_image2 = 'pgm';
            else
               if lower(format_image2(1)) == 'j',
                  format_image2 = 'jpg';
               else
                  if lower(format_image2(1)) == 'r',
                     format_image2 = 'ras';
                  else
                     disp('Invalid image format');
                     format_image2 = '0'; % Ask for format once again
                  end;
               end;
            end;
         end;
      end;
   end;
end;

ima_name = [image_name '.' format_image2];

READ IN IMAGE:

if format_image2(1) == 'p',
   if format_image2(2) == 'p',
      I = double(loadppm(ima_name));
   else
      I = double(loadpgm(ima_name));
   end;
else
   if format_image2(1) == 'r',
      I = readras(ima_name);
   else
      I = double(imread(ima_name));
   end;
end;

if size(I,3)>1,
   I = I(:,:,2);
end;

EXTRACT GRID CORNERS:

fprintf(1,'\nExtraction of the grid corners on the image\n');

disp('Window size for corner finder (wintx and winty):');
wintx = input('wintx ([] = 5) = ');
if isempty(wintx), wintx = 5; end;
wintx = round(wintx);
winty = input('winty ([] = 5) = ');
if isempty(winty), winty = 5; end;
winty = round(winty);

fprintf(1,'Window size = %dx%d\n',2*wintx+1,2*winty+1);


[x_ext,X_ext,n_sq_x,n_sq_y,ind_orig,ind_x,ind_y] = extract_grid(I,wintx,winty,fc,cc,kc);

save ext_data x_ext X_ext n_sq_x n_sq_y ind_orig ind_x ind_y

Published with MATLAB® R2015a