# What is the underlying function of 'interpolate' option of Volumes module

**URL:** <https://discourse.slicer.org/t/what-is-the-underlying-function-of-interpolate-option-of-volumes-module/1604>\
**Category:** Support\
**Created:** [December 6, 2017, 5:36pm UTC](https://discourse.slicer.org/t/what-is-the-underlying-function-of-interpolate-option-of-volumes-module/1604 "2017-12-06T17:36:55Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![muratmaga](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/muratmaga/32/3622_2.png) [@muratmaga](https://discourse.slicer.org/u/muratmaga)\
**Post date:** [December 6, 2017, 5:36pm UTC](https://discourse.slicer.org/t/what-is-the-underlying-function-of-interpolate-option-of-volumes-module/1604/1 "2017-12-06T17:36:55Z")

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I have a resampled volume which looks smoother when the interpolate option is checked. I would like to save the volume like that. What is the actual function it uses to do that?

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**Author:** ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)\
**Post date:** [December 6, 2017, 9:58pm UTC](https://discourse.slicer.org/t/what-is-the-underlying-function-of-interpolate-option-of-volumes-module/1604/2 "2017-12-06T21:58:48Z")

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That option controls how the image is sampled when scaled for display: nearest neighbor / linear (see [https://en.wikipedia.org/wiki/Image\_scaling](https://en.wikipedia.org/wiki/Image_scaling) for details). There is nothing to save - what you see is still the original volume.