EIDORS: Electrical Impedance Tomography and Diffuse Optical Tomography Reconstruction Software

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Effects of the Meshsize parameter in Netgen

Check Netgen is installed.

Setup: use default meshsize

Call netgen:

% Call Netgen $Id: meshsize_param01.m 1535 2008-07-26 15:36:27Z aadler $ 
electrodes_per_plane= 16;
number_of_planes= 1;
movement_pattern='radial_turn';
tank_height= 10;
finelevel=''; %finelevel='-fine'; Other option
refine_electrodes=0;
fno_max=1;
maxh= ''; %don't use max h
move_the_ball % CALL NETGEN

Reconstruct images:

% Reconstruct images $Id: meshsize_param02.m 1535 2008-07-26 15:36:27Z aadler $
imdl= mk_common_model('c2c2',16);
imdl.RtR_prior= @laplace_image_prior;
imdl.hyperparameter.value = 0.01;

th= linspace(0,2*pi,100); th(end)= [];
xcirc= 0.5+0.1*cos(th); ycirc= 0.1*sin(th);

subplot(121);
show_fem(img); view(90,60);

subplot(122);
show_fem(inv_solve( imdl, vh, vi(1)));
line(xcirc,ycirc,'Color',[0,0.5,0],'LineWidth',2);
axis image
ylabel(sprintf('No. Elems= %d', size(img.fwd_model.elems,1)));

print -dpng -r100 meshsize_param02a.png

Figure: Left: forward model Right: reconstructed image (with target position in green)

Calculate several meshsizes

for loop1 = 2
   switch loop1;
      case 1; finelevel='';          loop2max= 7;
      case 2; finelevel='-fine';     loop2max= 7;
      case 3; finelevel='-veryfine'; loop2max= 7;
   end
   for loop2 = 6:loop2max
      switch loop2;
         case 1; maxh= '-maxh=2.0';
         case 2; maxh= '-maxh=1.5';
         case 3; maxh= '-maxh=1.0';
         case 4; maxh= '-maxh=0.8';
         case 5; maxh= '-maxh=0.7';
         case 6; maxh= '-maxh=0.6';
         case 7; maxh= '-maxh=0.5';
      end
      move_the_ball % CALL NETGEN

      subplot(121); show_fem(img); view(90,60);

      subplot(122); show_fem(inv_solve( imdl, vh, vi(1))); axis image
      line(xcirc,ycirc,'Color',[0,0.5,0],'LineWidth',2);
      ylabel(sprintf('No. Elems= %d', size(img.fwd_model.elems,1)));

      fname= sprintf('meshsize_param03%c%c.png', loop1-1+'a', loop2-1+'a');
      print('-dpng','-r100', fname );
   end
end

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Figure: Left: forward model Right: reconstructed image (with target position in green)