Running subroutines found in this folder, in turn, require functions found in the irt package. Following are the steps to add irt to your matlab path:
$ cd ct-recon/digiNoise
$ wget https://github.com/smuzd/LD-CT-simulation/blob/master/I0.mat?raw=true
$ mv I0.mat\?raw\=true I0.mat
$ mv I0* ./data/matfiles/
$ cd ../..
$ wget https://web.eecs.umich.edu/~fessler/irt/fessler.tgz
$ tar -xvzf fessler.tgz
$ mv ct-recon/error_analysis/cho_lcd/fbp2_window.m irt/fbp/
$ mv irt ct-recon/ # move the irt package inside your ct-recon copy
$ cd ct-recon/irt
$ matlab
>> setup
>> cd ../digiNoise
DEMO on using IRT for the low-dose and normal-dose CT simulation and different filter-based FBP reconstruction
demo_fbp_w_filters
demo_nps_val_on_ldgc
DEMO on CT realizations using virtual CCT189 replica required for an observer model based performance testing
demo_nps_val_on_ldgc
demo_modified_xcat_realizations
demo_fbp_on_acr_module1