# Getting blue slice instead of grayscale vtkCutter

**URL:** https://discourse.vtk.org/t/getting-blue-slice-instead-of-grayscale-vtkcutter/8903
**Category:** Support
**Tags:** python
**Created:** [July 7, 2022, 1:26pm UTC](https://discourse.vtk.org/t/getting-blue-slice-instead-of-grayscale-vtkcutter/8903 "2022-07-07T13:26:19Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![olry](https://discourse.vtk.org/letter_avatar_proxy/v4/letter/o/0ea827/32.png) [@olry](https://discourse.vtk.org/u/olry)
#### Post date: [July 7, 2022, 1:26pm UTC](https://discourse.vtk.org/t/getting-blue-slice-instead-of-grayscale-vtkcutter/8903/1 "2022-07-07T13:26:19Z")

</div>

Hi everyone!

I’m reading uint16 numpy array using vtkImageImport and them try to cut one slice from this volume but I get a blue image only, whreas the volume is rendered in grayscale as needed. Could anyone please suggest why am I getting this blue image when cutting?

Here is a part of code I use:

for reading:  
dataImporter = vtk.vtkImageImport()  
dataImporter.SetImportVoidPointer(image)  
if image.dtype == np.uint8:  
dataImporter.SetDataScalarTypeToUnsignedChar()  
elif image.dtype == np.uint16:  
dataImporter.SetDataScalarTypeToUnsignedShort()  
dataImporter.SetNumberOfScalarComponents(1)

for cutting:  
def cut\_plane(self, j, obj, slices):  
import vtk

```
    # Create a plane to cut
    # XZ = (1,0,0) XY = (0,0,1), YZ = (0,1,0)
    plane = vtk.vtkPlane()
    plane.SetOrigin(slices[::-1])
    if j == 1:
        # axial
        plane.SetNormal(0, 0, 1)
    elif j == 2:
        plane.SetNormal(0, 1, 0)
    elif j == 3:
        plane.SetNormal(1, 0, 0)

    cutter = vtk.vtkCutter()
    cutter.SetCutFunction(plane)
    cutter.SetInputData(obj.GetMapper().GetInput())
    cutter.Update()

    return cutter

```

Thank you!  
Helga.