# itk:GPUImage::Graft cannot access protected member declared in class itk::GPUImage

**URL:** https://discourse.itk.org/t/itk-graft-cannot-access-protected-member-declared-in-class-itk-gpuimage/2715
**Category:** Beginner Questions
**Created:** [February 13, 2020, 9:57am UTC](https://discourse.itk.org/t/itk-graft-cannot-access-protected-member-declared-in-class-itk-gpuimage/2715 "2020-02-13T09:57:16Z")
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### Author: ![zhang-qiang-github](https://discourse.itk.org/user_avatar/discourse.itk.org/zhang-qiang-github/32/1183_2.png) [@zhang-qiang-github](https://discourse.itk.org/u/zhang-qiang-github)
#### Post date: [February 13, 2020, 9:57am UTC](https://discourse.itk.org/t/itk-graft-cannot-access-protected-member-declared-in-class-itk-gpuimage/2715/1 "2020-02-13T09:57:16Z")

</div>

I am starting my registration project. I modify the code: Examples/RegistrationITKv4/DeformableRegistration16, and it work.

Then, I want to use GPU to accelarate the program, and replace the DemonsRegistrationFilter with GPUDemonsRegistrationFilter, then the bug is reported:

error C2248 ‘itk::GPUImage\<VectorPixelType,3\>::Graft’: cannot access protected member declared in class ‘itk::GPUImage\<VectorPixelType,3\>’ d:\itk\_gpu\insighttoolkit-5.0.1\modules\registration\gpupdedeformable\include\itkGPUPDEDeformableRegistrationFilter.hxx

Could somebody provide a demo for GPU based Demons registration?

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