# Input for vector to scalar volume from jpg not working

**URL:** https://discourse.slicer.org/t/input-for-vector-to-scalar-volume-from-jpg-not-working/11746
**Category:** Support
**Created:** [May 28, 2020, 1:43pm UTC](https://discourse.slicer.org/t/input-for-vector-to-scalar-volume-from-jpg-not-working/11746 "2020-05-28T13:43:49Z")
**Posts on this page:** 3
**Page:** 1

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### Author: ![Pietro\_Ibba](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/pietro_ibba/32/4827_2.png) [@Pietro\_Ibba](https://discourse.slicer.org/u/Pietro_Ibba)
#### Post date: [May 28, 2020, 1:43pm UTC](https://discourse.slicer.org/t/input-for-vector-to-scalar-volume-from-jpg-not-working/11746/1 "2020-05-28T13:43:49Z")

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Operating system: Windows 10  
Slicer version: 4.10.2  
Expected behavior:  
Actual behavior:

I am sorry if this question was already posted.

I am trying to reconstruct a 3D model from an MRI series of jpg images, I am following the tutorial for the import of png images, so first after importing I set the image spacing and origin in the “volumes” module. Then when I try to input the vector volume in the “vector to scalar conveter” module, I cannot select the previously imported volume.

Am I doing something wrong?

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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: [May 28, 2020, 1:47pm UTC](https://discourse.slicer.org/t/input-for-vector-to-scalar-volume-from-jpg-not-working/11746/2 "2020-05-28T13:47:40Z")

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Maybe it is already a single-component (grayscale) volume. Can you check what value do you see in Volumes module / Volume information / Number of scalars? If you see 1 there then “Volume type” should be “Scalar” and you don’t need “Vector to scalar converter”. If you see 3 or 4 then you should see that “Volume type” is “Vector” and so the volume shows up in need “Vector to scalar converter” module’s input selector.

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### Author: ![Pietro\_Ibba](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/pietro_ibba/32/4827_2.png) [@Pietro\_Ibba](https://discourse.slicer.org/u/Pietro_Ibba)
#### Post date: [May 28, 2020, 2:23pm UTC](https://discourse.slicer.org/t/input-for-vector-to-scalar-volume-from-jpg-not-working/11746/3 "2020-05-28T14:23:00Z")

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Hi Andras, thank you for your reply, it was indeed already a greyscale volume!