# Extract the annotated plane in 3D image

**URL:** <https://discourse.slicer.org/t/extract-the-annotated-plane-in-3d-image/36799>\
**Category:** Development\
**Created:** [June 15, 2024, 3:55am UTC](https://discourse.slicer.org/t/extract-the-annotated-plane-in-3d-image/36799 "2024-06-15T03:55:56Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![musheng0624](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/musheng0624/32/76966_2.png) [@musheng0624](https://discourse.slicer.org/u/musheng0624)\
**Post date:** [June 15, 2024, 3:55am UTC](https://discourse.slicer.org/t/extract-the-annotated-plane-in-3d-image/36799/1 "2024-06-15T03:55:56Z")

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I am doing a view plane localization research. First I need to annotate the plane as the ground-truth. I use the “Markups” module of 3D Slicer to annotate the plane. But after i annotated the plane and export the json file. I used the “baseToNode” as the rotation matrix to extract the annotated plane, but i can not get the annotated plane. How can i get the annotated plane using python? Should I using the key “center” and “normal” in the json file?

 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/1/1/114ba23ab019467b2d4e784a94d2c921bea2919f.jpeg)

This is my annotate plane!

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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 15, 2024, 5:12am UTC](https://discourse.slicer.org/t/extract-the-annotated-plane-in-3d-image/36799/2 "2024-06-15T05:12:02Z")

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Yes, you can use `center` and `normal` properties in the json file. If you want to create a markup plane JSON file then you can follow this [example in the script repository](https://slicer.readthedocs.io/en/latest/developer_guide/script_repository.html#create-markup-plane-json-file-outside-slicer).