# Noise measurement 

**URL:** <https://discourse.slicer.org/t/noise-measurement/21605>\
**Category:** Support\
**Created:** [January 24, 2022, 10:08pm UTC](https://discourse.slicer.org/t/noise-measurement/21605 "2022-01-24T22:08:04Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![susmita\_afroz](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/susmita_afroz/32/13947_2.png) [@susmita\_afroz](https://discourse.slicer.org/u/susmita_afroz)\
**Post date:** [January 24, 2022, 10:08pm UTC](https://discourse.slicer.org/t/noise-measurement/21605/1 "2022-01-24T22:08:04Z")

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Operating system: Windows  
Slicer version: 4.11  
Expected behavior:  
Actual behavior:

I need help to measure noise from an image using 3D slicer. Need to compare noise from 3 images taken with different mA

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**Author:** ![Juicy](https://avatars.discourse-cdn.com/v4/letter/j/74df32/32.png) [@Juicy](https://discourse.slicer.org/u/Juicy)\
**Post date:** [January 25, 2022, 7:45am UTC](https://discourse.slicer.org/t/noise-measurement/21605/2 "2022-01-25T07:45:00Z")

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Use the segment editor to paint an area where you want to make the noise measurement. Then use the segment statistics module to get the standard deviation of the pixel values in the painted segment as a measure of the noise in the image.

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**Author:** ![susmita\_afroz](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/susmita_afroz/32/13947_2.png) [@susmita\_afroz](https://discourse.slicer.org/u/susmita_afroz)\
**Post date:** [January 25, 2022, 9:40pm UTC](https://discourse.slicer.org/t/noise-measurement/21605/3 "2022-01-25T21:40:25Z")

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Thank you very much Juicy.