# delete the polydata noises with connectivity filter

**URL:** https://discourse.vtk.org/t/delete-the-polydata-noises-with-connectivity-filter/12644
**Category:** Development
**Created:** [November 8, 2023, 11:50am UTC](https://discourse.vtk.org/t/delete-the-polydata-noises-with-connectivity-filter/12644 "2023-11-08T11:50:41Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![kimia\_ghodoosi](https://discourse.vtk.org/user_avatar/discourse.vtk.org/kimia_ghodoosi/32/7758_2.png) [@kimia\_ghodoosi](https://discourse.vtk.org/u/kimia_ghodoosi)
#### Post date: [November 8, 2023, 11:50am UTC](https://discourse.vtk.org/t/delete-the-polydata-noises-with-connectivity-filter/12644/1 "2023-11-08T11:50:41Z")

</div>

Hi!  
I want to delete noises from my polydata with connectivity filter.I think first I should specify all regions and then delete undesired regions, and finally, just have the largest region. But I don’t know how I can access to the regions’ ids to use DeleteSpecifiedRegion(int id). could you help me?  
(my code and my sample polydata is shown below)

 ![image](https://discourse.vtk.org/uploads/default/original/2X/6/6e0e9f2b0bd67031efbac2c204e3976cf0b196d8.jpeg)

```
vtkNew<vtkPolyDataConnectivityFilter> connectivityFilter;
connectivityFilter->SetInputData(polydata);
connectivityFilter->ColorRegionsOn();
connectivityFilter->SetExtractionModeToSpecifiedRegions();
for (int j=0; j<connectivityFilter-> GetNumberOfExtractedRegions()-1 ; j++){
    connectivityFilter->AddSpecifiedRegion(j); 
 }

connectivityFilter->DeleteSpecifiedRegion(int id);

```

@mwestphal