how to calculate number of pixels in an image based on number of mesh elements used to reconstruct the image?

I am using EIDORS of Matlab for image reconstruction.

This is the code.

I am getting an output image based on the type of model used in mk_common_model instruction. Now i want find the resolution and number of pixels in the image based on type of fem model and number of mesh elements used. How can i find this.

inv2d= eidors_obj('inv_model', 'EIT inverse');

inv2d.reconst_type= 'difference';

inv2d.jacobian_bkgnd.value= 1;

imdl= mk_common_model('g2c',16);

inv2d.fwd_model = imdl.fwd_model;

imdl.hyperparameter.value = 1e-8;% Change the hyperparameter value

imgr = inv_solve(imdl, vh, vi);

figure(1) show_fem(imgr);