# SimpleITK 2.1 Release Candidate 2

**URL:** <https://discourse.itk.org/t/simpleitk-2-1-release-candidate-2/4258>\
**Category:** Announcements\
**Tags:** csharp, r, java, simpleitk, python\
**Created:** [July 12, 2021, 3:33pm UTC](https://discourse.itk.org/t/simpleitk-2-1-release-candidate-2/4258 "2021-07-12T15:33:07Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**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:** [July 12, 2021, 3:33pm UTC](https://discourse.itk.org/t/simpleitk-2-1-release-candidate-2/4258/1 "2021-07-12T15:33:07Z")

</div>

# Announcement

Announcing the SimpleITK 2.1 Release Candidate 2!

Users and developers are encouraged to test the RC before the final release and report issues, bugs, and any compatibility problems. This is the final RC before the final the 2.1.0 release.

## Installing SimpleITK

Complete instructions on getting started with SimpleITK including downloading binaries or building SimpleITK can be found on the SimpleITK [Read the Docs web page](https://simpleitk.readthedocs.io/en/master/installation.html).

### Python Binary Downloads

- Python binary wheels are available for download. It is important to have the latest version of pip for correct wheel compatibility and installation. To install the latest SimpleITK package from GitHub releases:

```auto
python -m pip install --upgrade pip
python -m pip install --pre SimpleITK --find-links https://github.com/SimpleITK/SimpleITK/releases/tag/v2.1rc2

```

### Python Wheels for Apple ARM64

Binary Python Wheels for Apple ARM64 have been manually created and are available [GitHub.com](http://GitHub.com).

### Anaconda Binary Downloads

Conda packages are available from Anaconda Cloud on the `SimpleITK` channel. These can be installed with:

```auto
conda install -c simpleitk/label/dev simpleitk

```

# Release Notes

## New Features

- Add `ImageRegistrationMethod::StopRegistration` method
- Add `StopRegistration` method to Demons based registration filters
- Update `HistogramMatchingImageFilter` to use named “referenceImage” input for second input image.

## Bug Fixes

- R calls to nonexistent methods are now handled gracefully
- In `BinaryMagnitudeImageFilter` test, changed type from UInt32 to Int32 for defined C++ behavior, fixed Mac ARM testing failure.

## Documentation

- Minor grammar and spelling changes to gettingStarted
- Improve documentation for [registration sampling strategies](https://simpleitk.readthedocs.io/en/master/registrationOverview.html#sampling)
- Add example demonstration [Java Image buffer interface](https://simpleitk.readthedocs.io/en/master/link_JavaGetSetBuffer_docs.html)
- Add multiple language [examples for ImageIOSelection](https://simpleitk.readthedocs.io/en/master/link_ImageIOSelection_docs.html)
- Added a [Windows build page](https://simpleitk.readthedocs.io/en/master/buildingWindows.html)

## Compilation

- Fix comparison between signed and unsigned integer compiler warning
- Remove explicit instantiating of Image of deque of LabelObjectLine
- Update SWIG to 4 require in CMake find\_package

---

<div class="post-metadata">

**Author:** ![dchen](https://discourse.itk.org/user_avatar/discourse.itk.org/dchen/32/34_2.png) [@dchen](https://discourse.itk.org/u/dchen)\
**Post date:** [July 12, 2021, 6:56pm UTC](https://discourse.itk.org/t/simpleitk-2-1-release-candidate-2/4258/2 "2021-07-12T18:56:14Z")

</div>

Any and all feedback on the new Mac ARM Python wheels would be greatly appreciated.