# vtkITKImageReader on NIFTI (.nii) file format

**URL:** https://discourse.vtk.org/t/vtkitkimagereader-on-nifti-nii-file-format/6800
**Category:** Web
**Created:** [October 11, 2021, 4:24pm UTC](https://discourse.vtk.org/t/vtkitkimagereader-on-nifti-nii-file-format/6800 "2021-10-11T16:24:39Z")
**Posts on this page:** 1
**Showing post:** 4

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### Author: ![anonymous\_iguana](https://discourse.vtk.org/user_avatar/discourse.vtk.org/anonymous_iguana/32/3997_2.png) [@anonymous\_iguana](https://discourse.vtk.org/u/anonymous_iguana)
#### Post date: [October 12, 2021, 5:52pm UTC](https://discourse.vtk.org/t/vtkitkimagereader-on-nifti-nii-file-format/6800/4 "2021-10-12T17:52:32Z")

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I’m updating this with the (unrelated) cause of this problem. I traced the call to the [webWorkerPromise called here](https://github.com/InsightSoftwareConsortium/itk-js/blob/master/src/readImageArrayBuffer.js#L8) that was never being returned. That led me to look into the itk.js setup more carefully and I realized that I had not configured [webpack correctly per instructions here](https://insightsoftwareconsortium.github.io/itk-js/examples/webpack.html) so that the WebWorkers were available. However, since my app is based on Create React App, the webpack configs were not immediately changeable and I ended up using [craco-itk](https://github.com/InsightSoftwareConsortium/craco-itk) so that I could use the WebWorkers required for reading in the .nii format files. I will also mention that there is [Create ITK App](https://github.com/InsightSoftwareConsortium/create-itk-app) for bootstraping a React App, though it does use [CRACO](https://github.com/gsoft-inc/craco), so it’s not “100% CRA” but also not ejected.

All in all, the vtkITKImageReader was a bit of a red-herring but hopefully this can help someone in the future.

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_[View the full topic](https://discourse.vtk.org/t/vtkitkimagereader-on-nifti-nii-file-format/6800)._