# convert SimpleITK image to activiz vtkImageData in CSharp
**URL:** https://discourse.vtk.org/t/convert-simpleitk-image-to-activiz-vtkimagedata-in-csharp/3673
**Category:** Support
**Created:** [June 30, 2020, 9:35am UTC](https://discourse.vtk.org/t/convert-simpleitk-image-to-activiz-vtkimagedata-in-csharp/3673 "2020-06-30T09:35:37Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@langderyos](https://discourse.vtk.org/u/langderyos)
#### Post date: [June 30, 2020, 9:35am UTC](https://discourse.vtk.org/t/convert-simpleitk-image-to-activiz-vtkimagedata-in-csharp/3673/1 "2020-06-30T09:35:37Z")
Hello, everyone.
I’m trying to convert SimpleITK image to activiz vtkImageData in CSharp using vtkImageImport.
I compared eyery pixel value after convert itk.simple.image.It seems ok but when I want to use the new vtkImageData, exception thrown:“ System.AccessViolationException ”(located at Kitware.VTK.dll )
Here is my code.
ImageSeriesReader dicomReader = new ImageSeriesReader();
VectorString filenames = ImageSeriesReader.GetGDCMSeriesFileNames(“F:/tmp/l”);
dicomReader.SetFileNames(filenames);
itk.simple.Image image = dicomReader.Execute();
VectorDouble direction = image.GetDirection();
VectorDouble origin = image.GetOrigin();
VectorDouble spacing = image.GetSpacing();
VectorUInt32 size = image.GetSize();
ImageFileWriter writer1 = new ImageFileWriter();
writer1.SetFileName(“F:/tmp/image1.mhd”);
writer1.Execute(image);
string typeString = image.GetPixelIDTypeAsString();//“16-bit unsigned integer”
int len = 1;
for (int dim = 0; dim \< image.GetDimension(); dim++)
{
len \*= (int)size[dim];
}
IntPtr imageptr = image.GetBufferAsUInt16();
vtkImageImport imageImport = new vtkImageImport();
[//imageImport.SetImportVoidPointer](https://imageImport.SetImportVoidPointer)(imageptr);
imageImport.CopyImportVoidPointer(imageptr, len \* 2);//2bytes
imageImport.SetDataScalarTypeToUnsignedShort();
imageImport.SetWholeExtent(0, (int)size[0] - 1, 0, (int)size[1] - 1, 0, (int)size[2] - 1);
imageImport.SetDataExtentToWholeExtent();
imageImport.SetDataSpacing(spacing[0], spacing[1], spacing[2]);
imageImport.Update();
imageData = imageImport.GetOutput();
imageData.SetOrigin(origin[0], origin[1], origin[2]);
imageData.SetSpacing(spacing[0], spacing[1], spacing[2]);
imageData.SetExtent(0, (int)size[0] - 1, 0, (int)size[1] - 1, 0, (int)size[2] - 1);
imageData.SetNumberOfScalarComponents(1);
for (uint i = 0; i \< size[0]; i++)
{
for (uint j = 0; j \< size[1]; j++)
{
for (uint k = 0; k \< size[0]; k++)
{
VectorUInt32 indexVector = new VectorUInt32 { i,j,k};
UInt16 pixelValue = image.GetPixelAsUInt16(indexVector);
if(pixelValue!= imageData.GetScalarComponentAsDouble((int)i, (int)j, (int)k, 0))
{
MessageBox.Show(“not equal”);
return;
}
}
}
}
vtkMetaImageWriter writer = new vtkMetaImageWriter();
writer.SetInput(imageData);
writer.SetFileName(@“F:/tmp/image2.mhd”);
writer.Update();[//System.AccessViolationException](https://System.AccessViolationException)
---
### Author:  [@nober](https://discourse.vtk.org/u/nober)
#### Post date: [June 30, 2020, 9:59am UTC](https://discourse.vtk.org/t/convert-simpleitk-image-to-activiz-vtkimagedata-in-csharp/3673/2 "2020-06-30T09:59:41Z")
It is difficult to see some people use activiz for development. There is too little information in this regard. It is too exciting to see someone asking questions. I am not alone. I use the following code for itk to vtk images. Conversion, it works very well.You may need to pay attention to the problem of image flipping. Hope it helps you.
> public vtkImageData Excute(sitk.Image itkImage)
> {
> var width = (int)itkImage.GetWidth();
> var height = (int)itkImage.GetHeight();
> var depth = (int)itkImage.GetDepth();
> var numberOfPoints = itkImage.GetNumberOfPixels();
> var origin = itkImage.GetOrigin();
> var spacing = itkImage.GetSpacing();
> vtkImage.SetOrigin(origin[0], origin[1], origin[2]);
> vtkImage.SetSpacing(spacing[0], spacing[1], spacing[2]);
> vtkImage.SetExtent(0, width - 1, 0, height - 1, 0, depth - 1);
> vtkImage.AllocateScalars();
> var vp = vtkImage.GetScalarPointer();
> var ip = itkImage.GetBufferAsInt16();
> var length = (uint)(numberOfPoints \* 2);
> ip.CopyTo(vp, length);
> return vtkImage;
> }
```
[DllImport("kernel32.dll", EntryPoint = "CopyMemory", SetLastError = false)]
public static extern void CopyMemory(IntPtr dest, IntPtr src, uint count);
public static void CopyTo(this IntPtr src, IntPtr dest, uint len)
{
CopyMemory(dest, src, len);
}
```
---
### Author:  [@langderyos](https://discourse.vtk.org/u/langderyos)
#### Post date: [June 30, 2020, 11:02am UTC](https://discourse.vtk.org/t/convert-simpleitk-image-to-activiz-vtkimagedata-in-csharp/3673/3 "2020-06-30T11:02:18Z")
Thanks for your reply.
Glad to meet you!
I tested your code, but got the same result as before.
Maybe there is a problem with my visual studio project settings.Or I don’t understand the vtkImageData correctly.
May I ask how you handle the “vtkImage” in your code?
I just initialized it like “new vtkImageData” and did some properties modify.
---
### Author:  [@nober](https://discourse.vtk.org/u/nober)
#### Post date: [June 30, 2020, 11:04am UTC](https://discourse.vtk.org/t/convert-simpleitk-image-to-activiz-vtkimagedata-in-csharp/3673/4 "2020-06-30T11:04:04Z")
```
vtkImage = vtkImageData.New();
vtkImage.SetScalarTypeToShort();
vtkImage.SetNumberOfScalarComponents(1);
```
---
### Author:  [@langderyos](https://discourse.vtk.org/u/langderyos)
#### Post date: [June 30, 2020, 11:15am UTC](https://discourse.vtk.org/t/convert-simpleitk-image-to-activiz-vtkimagedata-in-csharp/3673/5 "2020-06-30T11:15:30Z")
Thanks.
It looks same.I will search the cause in other respects.
---
### Author:  [@langderyos](https://discourse.vtk.org/u/langderyos)
#### Post date: [July 24, 2020, 6:43pm UTC](https://discourse.vtk.org/t/convert-simpleitk-image-to-activiz-vtkimagedata-in-csharp/3673/6 "2020-07-24T18:43:03Z")
When I change “writer.Update()” to “writer.Write()”, I know what happened.