# cast scalar volume

**URL:** <https://discourse.slicer.org/t/cast-scalar-volume/13546>\
**Category:** Support\
**Created:** [September 18, 2020, 1:41pm UTC](https://discourse.slicer.org/t/cast-scalar-volume/13546 "2020-09-18T13:41:46Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![jianyuan](https://avatars.discourse-cdn.com/v4/letter/j/6bbea6/32.png) [@jianyuan](https://discourse.slicer.org/u/jianyuan)\
**Post date:** [September 18, 2020, 1:41pm UTC](https://discourse.slicer.org/t/cast-scalar-volume/13546/1 "2020-09-18T13:41:46Z")

</div>

I faied in the segmentation of tumors with the growcuteffect. I cast PET images to ‘short’ type (using Cast Scalar Volume module). However, the regions of high intensity turned black in “shot” type, and it seems that 3D slicer could not differentiate these regions from the background. ![NO1](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/3/f/3fec3533f365d4498090389518493c1d45096631.png)

---

<div class="post-metadata">

**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:** [September 18, 2020, 1:44pm UTC](https://discourse.slicer.org/t/cast-scalar-volume/13546/2 "2020-09-18T13:44:04Z")

</div>

It seems that you image contains values that cannot be represented in `short` type. To resolve this, you can [rescale the image intensity](https://discourse.slicer.org/t/image-quantization-techniques/13420/2) before casting to a different scalar type.

---

<div class="post-metadata">

**Author:** ![jianyuan](https://avatars.discourse-cdn.com/v4/letter/j/6bbea6/32.png) [@jianyuan](https://discourse.slicer.org/u/jianyuan)\
**Post date:** [September 18, 2020, 5:24pm UTC](https://discourse.slicer.org/t/cast-scalar-volume/13546/3 "2020-09-18T17:24:17Z")

</div>

Thanks! Is it possible to resolve this problem using 3D slicer？ I wonder how to rescale the image intensity using 3D slicer?

---

<div class="post-metadata">

**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:** [September 18, 2020, 6:34pm UTC](https://discourse.slicer.org/t/cast-scalar-volume/13546/4 "2020-09-18T18:34:22Z")

</div>

Yes, see which modules you can use to rescale image intensity at the link in my previous post.