# SimpleITK 3.0.0 Alpha 3

**URL:** <https://discourse.itk.org/t/simpleitk-3-0-0-alpha-3/7733>\
**Category:** Announcements\
**Tags:** csharp, r, java, simpleitk, python\
**Created:** [March 18, 2026, 2:16pm UTC](https://discourse.itk.org/t/simpleitk-3-0-0-alpha-3/7733 "2026-03-18T14:16:23Z")\
**Posts on this page:** 1\
**Showing post:** 5

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**Author:** ![blowekamp](https://discourse.itk.org/user_avatar/discourse.itk.org/blowekamp/32/79_2.png) [@blowekamp](https://discourse.itk.org/u/blowekamp)\
**Post date:** [March 18, 2026, 8:22pm UTC](https://discourse.itk.org/t/simpleitk-3-0-0-alpha-3/7733/5 "2026-03-18T20:22:57Z")

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The release notes are correct for SimpleITK, in that it defaults to the new behavior. I believe that there was a discussion some place about why the legacy behavior was wrong it would probably be good to include that in the notes. So you know where the discussion occoured? Is this it: [Sobel operator extended for 4D, legacy support for 3D, OK?](https://discourse.itk.org/t/sobel-operator-extended-for-4d-legacy-support-for-3d-ok/7699)

> [@Niels\_Dekker](#):
>
> For your information, at the moment, ITK (v6.0b02) only uses the new, more consistent coefficients for 3D Sobel when you explicitly _disable_ `UseLegacyOperatorCoefficients`. Or when you enable `ITK_FUTURE_LEGACY_REMOVE`.

SimpleITK has the defaults explicitly specified as UseLegacyOperatorCoefficients=OFF.

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