undistort_image.m

这是一个很好的标定工具箱

%%% INPUT THE IMAGE FILE NAME:

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

KK = [fc(1) alpha_c*fc(1) cc(1);0 fc(2) cc(2) ; 0 0 1];

disp('Program that undistorts images');
disp('The intrinsic camera parameters are assumed to be known (previously computed)');

fprintf(1,'\n');

quest = input('Do you want to undistort all the calibration images ([],0) or a new image (1)? ');

if isempty(quest),
   quest = 0;
end;

if ~quest,

	if ~exist(['I_' num2str(ind_active(1))]),
   	ima_read_calib;
   end;
   
   check_active_images;   
   
   format_image2 = format_image;
   if format_image2(1) == 'j',
      format_image2 = 'bmp';
   end;
   
   for kk = 1:n_ima,
      
      if exist(['I_' num2str(kk)]),
      
      	eval(['I = I_' num2str(kk) ';']);
      	[I2] = rect(I,eye(3),fc,cc,kc,KK);
	
   		if ~type_numbering,   
      		number_ext =  num2str(image_numbers(kk));
   		else
      		number_ext = sprintf(['%.' num2str(N_slots) 'd'],image_numbers(kk));
   		end;
   		
      	ima_name2 = [calib_name '_rect' number_ext '.' format_image2];
      	
      	fprintf(1,['Saving undistorted image under ' ima_name2 '...\n']);
         
         
         if format_image2(1) == 'p',
            if format_images2(2) == 'p',
               saveppm(ima_name2,uint8(round(I2)));
            else
               savepgm(ima_name2,uint8(round(I2)));
            end;
         else
            if format_image2(1) == 'r',
               writeras(ima_name2,round(I2),gray(256));
            else
               imwrite(uint8(round(I2)),gray(256),ima_name2,format_image2);
            end;
         end;
         
         
      end;
      
   end;
   
   fprintf(1,'done\n');

else
   
   dir;
   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;


if (size(I,1)>ny)|(size(I,2)>nx),
   I = I(1:ny,1:nx);
end;


	%% SHOW THE ORIGINAL IMAGE:
	
	figure(2);
	image(I);
	colormap(gray(256));
	title('Original image (with distortion) - Stored in array I');
	drawnow;
	
	
	%% UNDISTORT THE IMAGE:
	
	fprintf(1,'Computing the undistorted image...')
	
   [I2] = rect(I,eye(3),fc,cc,kc,alpha_c,KK);
   
   fprintf(1,'done\n');
	
	figure(3);
	image(I2);
	colormap(gray(256));
	title('Undistorted image - Stored in array I2');
   drawnow;
   
   
   %% SAVE THE IMAGE IN FILE:
   
   ima_name2 = [image_name '_rect.' format_image2];
   
   fprintf(1,['Saving undistorted image under ' ima_name2 '...']);
   
   if format_image2(1) == 'p',
      if format_images2(2) == 'p',
	      saveppm(ima_name2,uint8(round(I2)));
      else
	      savepgm(ima_name2,uint8(round(I2)));
      end;
   else
      if format_image2(1) == 'r',
         writeras(ima_name2,round(I2),gray(256));
      else
         imwrite(uint8(round(I2)),gray(256),ima_name2,format_image2);
      end;
   end;
   
   fprintf(1,'done\n');
      
end;