# GetRGBACharPixelData still get alphaChannel even after SetAlphaBitPlanes(0)?

**URL:** https://discourse.vtk.org/t/getrgbacharpixeldata-still-get-alphachannel-even-after-setalphabitplanes-0/11993
**Category:** Support
**Created:** [July 21, 2023, 4:21am UTC](https://discourse.vtk.org/t/getrgbacharpixeldata-still-get-alphachannel-even-after-setalphabitplanes-0/11993 "2023-07-21T04:21:32Z")
**Posts on this page:** 3
**Page:** 1

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### Author: ![gpu](https://discourse.vtk.org/letter_avatar_proxy/v4/letter/g/e47c2d/32.png) [@gpu](https://discourse.vtk.org/u/gpu)
#### Post date: [July 21, 2023, 4:21am UTC](https://discourse.vtk.org/t/getrgbacharpixeldata-still-get-alphachannel-even-after-setalphabitplanes-0/11993/1 "2023-07-21T04:21:32Z")

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GetRGBACharPixelData still get alphaChannel even after SetAlphaBitPlanes(0)?

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### Author: ![sankhesh](https://discourse.vtk.org/user_avatar/discourse.vtk.org/sankhesh/32/73_2.png) [@sankhesh](https://discourse.vtk.org/u/sankhesh)
#### Post date: [July 21, 2023, 1:35pm UTC](https://discourse.vtk.org/t/getrgbacharpixeldata-still-get-alphachannel-even-after-setalphabitplanes-0/11993/2 "2023-07-21T13:35:30Z")

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VTK uses RGBA buffers always. It was a choice made because RGBA buffers were more universally supported across most hardware drivers over RGB buffers at the time of the OpenGL refactor.

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### Author: ![gpu](https://discourse.vtk.org/letter_avatar_proxy/v4/letter/g/e47c2d/32.png) [@gpu](https://discourse.vtk.org/u/gpu)
#### Post date: [July 24, 2023, 1:26am UTC](https://discourse.vtk.org/t/getrgbacharpixeldata-still-get-alphachannel-even-after-setalphabitplanes-0/11993/3 "2023-07-24T01:26:20Z")

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thanks.  
So how to support RGB ? is there related API should be set in VTK?  
after SetAlphaBitPlanes(0) VTK still use RGBA ?  
and GetPixelData seems will return RGB buffer after SetAlphaBitPlanes(0).  
moreover, Window2Image seems to ALWAYS return RGB buffer.