diff --git a/MATLAB/Algorithms/PICCS.m b/MATLAB/Algorithms/PICCS.m
index 792de229..459dfaf0 100644
--- a/MATLAB/Algorithms/PICCS.m
+++ b/MATLAB/Algorithms/PICCS.m
@@ -199,7 +199,7 @@
     end
     if (iter==1 && verbose==1)
         expected_time=toc*maxiter;
-        disp('ADS-POCS');
+        disp('PICCS');
         disp(['Expected duration  :    ',secs2hms(expected_time)]);
         disp(['Exected finish time:    ',datestr(datetime('now')+seconds(expected_time))]);
         disp('');
diff --git a/MATLAB/Utilities/computeV.m b/MATLAB/Utilities/computeV.m
index 2150c703..21980d3d 100644
--- a/MATLAB/Utilities/computeV.m
+++ b/MATLAB/Utilities/computeV.m
@@ -8,7 +8,6 @@
 end
     
 V=zeros(geo.nVoxel(1),geo.nVoxel(2) ,length(alphablocks),'single');
-%geo.offDetector(1) = geo.offDetector(1) + (geo.DSD(1) / geo.DSO(1)) * geo.COR(1);  
 geo=checkGeo(geo,angles);
 
 if ~isfield(geo,'mode')||~strcmp(geo.mode,'parallel')
@@ -16,10 +15,9 @@
         auxang=alphablocks{ii};
         auxindex=orig_index{ii};
         auxgeo = geo;
-        % expand the detector to avoiding zeros in backprojection
-        maxsize=max(auxgeo.sVoxel+geo.offOrigin(:,auxindex),[],2);
-        auxgeo.sDetector=max(auxgeo.sDetector , [maxsize(1); maxsize(3)] *geo.DSD/geo.DSO);
-        auxgeo.dDetector = auxgeo.sDetector ./ auxgeo.nDetector;
+        % shrink the volume to avoiding zeros in backprojection
+        auxgeo.sVoxel = auxgeo.sVoxel * max(auxgeo.sVoxel(1:2)/norm(auxgeo.sVoxel(1:2),2)) * 0.9;
+        auxgeo.dVoxel = auxgeo.sVoxel ./ auxgeo.nVoxel;
         % subset of projection angles
         auxgeo.DSD = geo.DSD(auxindex);
         auxgeo.DSO = geo.DSO(auxindex);
@@ -27,10 +25,10 @@
         auxgeo.offDetector = geo.offDetector(:,auxindex);
         auxgeo.rotDetector = geo.rotDetector(:,auxindex);
         auxgeo.COR = geo.COR(auxindex);
-        %auxgeo=geo;
-        V(:,:,ii) = mean(Atb(ones(geo.nDetector(2),geo.nDetector(1),size(auxang,2),'single'),auxgeo,auxang,'gpuids',gpuids),3)+0.000001;
+                V(:,:,ii) = mean(Atb(ones(geo.nDetector(2),geo.nDetector(1),size(auxang,2),'single'),auxgeo,auxang, 'gpuids', gpuids),3);
+
+        %V(:,:,ii) = mean(Atb(ones(geo.nDetector(2),geo.nDetector(1),length(auxang),'single'),auxgeo,auxang, 'gpuids', gpuids),3);
     end
-    V(V==0.0)=Inf;
 else
     for ii=1:length(alphablocks)
         V(:,:,ii)=ones(geo.nVoxel(1:2).','single')*length(alphablocks{ii});