# why are preview result and apply result different in threshold segmentation？ 

**URL:** <https://discourse.slicer.org/t/why-are-preview-result-and-apply-result-different-in-threshold-segmentation/12050>\
**Category:** Support\
**Tags:** segmentation\
**Created:** [June 16, 2020, 2:22am UTC](https://discourse.slicer.org/t/why-are-preview-result-and-apply-result-different-in-threshold-segmentation/12050 "2020-06-16T02:22:35Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![SummerZ2020](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/summerz2020/32/7137_2.png) [@SummerZ2020](https://discourse.slicer.org/u/SummerZ2020)\
**Post date:** [June 16, 2020, 2:22am UTC](https://discourse.slicer.org/t/why-are-preview-result-and-apply-result-different-in-threshold-segmentation/12050/1 "2020-06-16T02:22:35Z")

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Operating system:windows  
Slicer version:4.10.2 and 4.11  
Expected behavior:the segmentation result after the “Apply” button is clicked should be same with the preview result in Threshold segmentation.  
Actual behavior: the segmentation result after the “Apply” button is clicked is worse than the preview result in Threshold segmentation.  
ps:The image thickness is 5mm.

 ![apply](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/d/b/db4252b8b35dbc524f5d3d6c8ce6ffc86c211fbd.png) ![preview](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/a/b/ab8700487d8e6d918b323ec3ac065beb899967e6.png)

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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:** [June 16, 2020, 2:30am UTC](https://discourse.slicer.org/t/why-are-preview-result-and-apply-result-different-in-threshold-segmentation/12050/2 "2020-06-16T02:30:24Z")

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Preview is displayed at the screen resolution, but when you apply the threshold then the segmentation’s resolution is used. The preview just looks smoother, but it actually contains the same information as the thresholding result.

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**Author:** ![SummerZ2020](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/summerz2020/32/7137_2.png) [@SummerZ2020](https://discourse.slicer.org/u/SummerZ2020)\
**Post date:** [June 17, 2020, 6:38am UTC](https://discourse.slicer.org/t/why-are-preview-result-and-apply-result-different-in-threshold-segmentation/12050/4 "2020-06-17T06:38:06Z")

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Thanks for your answer. but it seems that it is not caused only by the resolution as the result difference is differ widely.And some pixel points value is not reasonable, for example, the pixel value is smaller when it looks more lighter(white) obviously. I tried to install the latest version (4.11 2020.6.15), it works better in this senario. thanks again. 😀