1  %=======================================================================


2  % Copyright 20082015, LEGI UMR 5519 / CNRS UJF GINP, Grenoble, France


3  % http://www.legi.grenobleinp.fr


4  % Joel.Sommeria  Joel.Sommeria (A) legi.cnrs.fr


5  %


6  % This file is part of the toolbox UVMAT.


7  %


8  % UVMAT is free software; you can redistribute it and/or modify


9  % it under the terms of the GNU General Public License as published


10  % by the Free Software Foundation; either version 2 of the license,


11  % or (at your option) any later version.


12  %


13  % UVMAT is distributed in the hope that it will be useful,


14  % but WITHOUT ANY WARRANTY; without even the implied warranty of


15  % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the


16  % GNU General Public License (see LICENSE.txt) for more details.


17  %=======================================================================


18 


19  %go_calib_optim


20  %


21  %Main calibration function. Computes the intrinsic andextrinsic parameters.


22  %Runs as a script.


23  %


24  %INPUT: x_1,x_2,x_3,...: Feature locations on the images


25  % X_1,X_2,X_3,...: Corresponding grid coordinates


26  %


27  %OUTPUT: fc: Camera focal length


28  % cc: Principal point coordinates


29  % alpha_c: Skew coefficient


30  % kc: Distortion coefficients


31  % KK: The camera matrix (containing fc and cc)


32  % omc_1,omc_2,omc_3,...: 3D rotation vectors attached to the grid positions in space


33  % Tc_1,Tc_2,Tc_3,...: 3D translation vectors attached to the grid positions in space


34  % Rc_1,Rc_2,Rc_3,...: 3D rotation matrices corresponding to the omc vectors


35  %


36  %Method: Minimizes the pixel reprojection error in the least squares sense over the intrinsic


37  % camera parameters, and the extrinsic parameters (3D locations of the grids in space)


38  %


39  %Note: If the intrinsic camera parameters (fc, cc, kc) do not exist before, they are initialized through


40  % the function init_intrinsic_param.m. Otherwise, the variables in memory are used as initial guesses.


41  %


42  %Note: The row vector active_images consists of zeros and ones. To deactivate an image, set the


43  % corresponding entry in the active_images vector to zero.


44  %


45  %VERY IMPORTANT: This function works for 2D and 3D calibration rigs, except for init_intrinsic_param.m


46  %that is so far implemented to work only with 2D rigs.


47  %In the future, a more general function will be there.


48  %For now, if using a 3D calibration rig, set quick_init to 1 for an easy initialization of the focal length


49 


50  if ~exist('rosette_calibration','var')


51  rosette_calibration = 0;


52  end;


53 


54  if ~exist('n_ima'),


55  data_calib; % Load the images


56  click_calib; % Extract the corners


57  end;


58 


59 


60  check_active_images;


61 


62  check_extracted_images;


63 


64  check_active_images;


65 


66  desactivated_images = [];


67 


68  recompute_extrinsic = (length(ind_active) < 100); % if there are too many images, do not spend time recomputing the extrinsic parameters twice..


69 


70  if (rosette_calibration)


71  %%% Special Setting for the Rosette:


72  est_dist = ones(5,1);


73  end;


74 


75 


76  %%% MAIN OPTIMIZATION CALL!!!!! (look into this function for the details of implementation)


77  go_calib_optim_iter;


78 


79 


80  if ~isempty(desactivated_images),


81 


82  param_list_save = param_list;


83 


84  fprintf(1,'\nNew optimization including the images that have been deactivated during the previous optimization.\n');


85  active_images(desactivated_images) = ones(1,length(desactivated_images));


86  desactivated_images = [];


87 


88  go_calib_optim_iter;


89 


90  if ~isempty(desactivated_images),


91  fprintf(1,['List of images left desactivated: ' num2str(desactivated_images) '\n' ] );


92  end;


93 


94  param_list = [param_list_save(:,1:end1) param_list];


95 


96  end;


97 


98 


99  %%%%%%%%%%%%%%%%%%%% GRAPHICAL OUTPUT %%%%%%%%%%%%%%%%%%%%%%%%


100 


101  %graphout_calib;


102 

