# LabelMapToLabelImageFilter\`s output is an image with white color
**URL:** https://discourse.itk.org/t/labelmaptolabelimagefilter-s-output-is-an-image-with-white-color/5316
**Category:** Algorithms
**Tags:** itk, c
**Created:** [September 5, 2022, 9:44am UTC](https://discourse.itk.org/t/labelmaptolabelimagefilter-s-output-is-an-image-with-white-color/5316 "2022-09-05T09:44:12Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@Bugmaker](https://discourse.itk.org/u/Bugmaker)
#### Post date: [September 5, 2022, 9:44am UTC](https://discourse.itk.org/t/labelmaptolabelimagefilter-s-output-is-an-image-with-white-color/5316/1 "2022-09-05T09:44:12Z")
I want to use the ConnectedComponentImageFilter to delete the false positive area, and pass the result through other filters ( **LabelImageToShapeLabelMapFilter** , **LabelMap** , **LabelMapToLabelImageFilter** namely) to convert into image.
I find the background of the final result turn white and that the white background obscured the label.
However, when i use itk-snap to update, the 3d volume is right, and Each vertebra is clearly segmented.
```auto
typedef itk::Image ImageTypeFloat;
typedef itk::Image ImageSeg;
using LabelObject = itk::ShapeLabelObject;
using LabelMap = itk::LabelMap;
using ConnectComment = itk::ConnectedComponentImageFilter;
using LabelImageToLabelMapFilter = itk::LabelImageToShapeLabelMapFilter;
using L2IType = itk::LabelMapToLabelImageFilter;
using LabelShapeKeepNObject = itk::LabelShapeKeepNObjectsImageFilter;
using ImageRegionIterator = itk::ImageRegionConstIterator;
using ImageIterator = itk::ImageRegionIterator;
ConnectComment::Pointer connectcomment = ConnectComment::New();
WriteType::Pointer writer = WriteType::New();
ImageIOTypeNII::Pointer niftio = ImageIOTypeNII::New();
connectcomment->SetInput(img);
connectcomment->SetBackgroundValue(0);
connectcomment->Update();
LabelImageToLabelMapFilter::Pointer limgtmap = LabelImageToLabelMapFilter::New();
limgtmap->SetInput(connectcomment->GetOutput());
limgtmap->Update();
LabelMap::Pointer labelmap = limgtmap->GetOutput();
for (float label = 0; label < labelmap->GetNumberOfLabelObjects(); label++)
{
const LabelObject* labelobject = labelmap->GetLabelObject(label);
labelobject->Print(std::cout);
std::cout << "-------------------------------------------------------" << std::endl;
}
std::cout << "--------------------------------Process------------------------" << std::endl;
std::vectorfilter_objects;
for (LabelMap::Iterator in2(labelmap); !in2.IsAtEnd(); ++in2)
{
if (in2.GetLabelObject()->GetNumberOfPixels() < 10000)
filter_objects.emplace_back(in2.GetLabelObject());
}
for (int i = 0; i < filter_objects.size(); i++)
labelmap->RemoveLabelObject(filter_objects[i]);
L2IType::Pointer l2i = L2IType::New();
l2i->SetInput(labelmap);
l2i->Update();
ImageTypeFloat::Pointer res = l2i->GetOutput();
res->SetSpacing(img->GetSpacing());
res->SetDirection(img->GetDirection());
writer->SetImageIO(niftio);
writer->SetFileName("connect_.nii.gz");
writer->SetInput(res);
writer->Update();
```
the **final result** i have mentioned is **res**
**The res image:**
**ITK-Snap seg:**
---
### Author:  [@Bugmaker](https://discourse.itk.org/u/Bugmaker)
#### Post date: [September 7, 2022, 7:01am UTC](https://discourse.itk.org/t/labelmaptolabelimagefilter-s-output-is-an-image-with-white-color/5316/2 "2022-09-07T07:01:01Z")
I solve this problem by changing the itk::LabelImageToShapeLabelMapFilter`s in input datatype and output datatype into Int instead of Float.
it is seems that there is something wrong with this filter in converting datatype.