ENH: Ingest ITKSplitComponents into Modules/Filtering

Modules/Filtering/SplitComponents/CMakeLists.txt

@@ -0,0 +1,9 @@
+project(SplitComponents)
+
+if(POLICY CMP135)
+  cmake_policy(SET CMP135 NEW)
+endif()
+
+# set(SplitComponents_LIBRARIES SplitComponents) # header-only module, so no libraries
+
+itk_module_impl()

Modules/Filtering/SplitComponents/LICENSE

@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        https://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       https://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

Modules/Filtering/SplitComponents/README.md

@@ -0,0 +1,41 @@
+# SplitComponents
+
+In-tree ITK module providing `itk::SplitComponentsImageFilter` — a
+filter that splits a vector / covariant-vector / symmetric-second-rank-
+tensor image into one scalar component image per pixel-component.
+Useful for visualising, post-processing, or independently filtering
+the channels of multi-component images.
+
+## Origin
+
+Ingested from the standalone remote module
+[**InsightSoftwareConsortium/ITKSplitComponents**](https://github.com/InsightSoftwareConsortium/ITKSplitComponents)
+on 2026-05-05, at upstream commit
+[`94fde65c`](https://github.com/InsightSoftwareConsortium/ITKSplitComponents/commit/94fde65cae6883c9a0f1508c37c501c2ad989cdd).
+The upstream repository will be archived read-only after this PR
+merges; it remains reachable at the URL above.
+
+## What lives here
+
+Per the v4 ingestion strategy (see
+`Utilities/Maintenance/RemoteModuleIngest/INGESTION_STRATEGY_v4.md`),
+only paths matching the narrow whitelist
+(`Utilities/Maintenance/RemoteModuleIngest/whitelists/SplitComponents.list`)
+crossed the merge boundary:
+
+- `include/` — public C++ headers (header-only module; no `src/`).
+- `test/` — CTest drivers and content-link stubs.
+- `wrapping/` — Python wrapping descriptors.
+- `CMakeLists.txt`, `itk-module.cmake` — module metadata.
+- `LICENSE` — original Apache-2.0 license text.
+
+Upstream-only artifacts (CI dashboards, packaging, `apps/`,
+`article/`, `binder/`, `examples/`, `images/`, `.github/`,
+`pyproject.toml`, etc.) were explicitly excluded; the upstream
+commit graph and authorship history are otherwise preserved through
+a `--no-ff --allow-unrelated-histories` Mode-A merge.
+
+## Building
+
+SplitComponents is enabled by default once `Module_SplitComponents=ON`
+is set; in CI it is enabled via `pyproject.toml`'s `configure-ci` task.

Modules/Filtering/SplitComponents/include/itkSplitComponentsImageFilter.h

@@ -0,0 +1,106 @@
+/*=========================================================================
+ *
+ *  Copyright NumFOCUS
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *         https://www.apache.org/licenses/LICENSE-2.0.txt
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ *=========================================================================*/
+#ifndef itkSplitComponentsImageFilter_h
+#define itkSplitComponentsImageFilter_h
+
+#include "itkFixedArray.h"
+#include "itkImageToImageFilter.h"
+
+namespace itk
+{
+
+/** \class SplitComponentsImageFilter
+ *
+ * \brief Extract components of an Image with multi-component pixels.
+ *
+ * This class extracts components of itk::Image of itk::Vector's
+ * itk::CovariantVector, itk::SymmetricSecondRankTensor, or other classes that
+ * have the same interface.  The interface must implement ValueType operator[] (
+ * unsigned int ).
+ *
+ * It puts an image on every output corresponding to each component.
+ *
+ * \ingroup SplitComponents
+ *
+ * \sa VectorImageToImageAdaptor
+ * \sa Vector
+ * \sa CovariantVector
+ * \sa SymmetricSecondRankTensor
+ * \sa DiffusionTensor3D
+ * \sa NthElementImageAdaptor
+ */
+template <typename TInputImage, typename TOutputImage, unsigned int TComponents = TInputImage::ImageDimension>
+class ITK_TEMPLATE_EXPORT SplitComponentsImageFilter : public ImageToImageFilter<TInputImage, TOutputImage>
+{
+public:
+  ITK_DISALLOW_COPY_AND_MOVE(SplitComponentsImageFilter);
+
+  /** ImageDimension enumeration. */
+  static constexpr unsigned int ImageDimension = TInputImage::ImageDimension;
+  /** Components enumeration. */
+  static constexpr unsigned int Components = TComponents;
+
+  /** Image types. */
+  using InputImageType = TInputImage;
+  using OutputImageType = TOutputImage;
+  using InputPixelType = typename InputImageType::PixelType;
+  using OutputPixelType = typename OutputImageType::PixelType;
+  using OutputRegionType = typename OutputImageType::RegionType;
+
+  /** Standard class type alias. */
+  using Self = SplitComponentsImageFilter;
+  using Superclass = ImageToImageFilter<InputImageType, OutputImageType>;
+  using Pointer = SmartPointer<Self>;
+  using ConstPointer = SmartPointer<const Self>;
+
+  using ComponentsMaskType = FixedArray<bool, TComponents>;
+
+  /** Run-time type information (and related methods). */
+  itkOverrideGetNameOfClassMacro(SplitComponentsImageFilter);
+
+  /** Method of creation through the object factory. */
+  itkNewMacro(Self);
+
+  /** Set/Get the components mask.  The mask is as long as the number of
+   * components, and only values in the mask that evaluate are true will be
+   * populated in the output.  The default is all true. */
+  itkSetMacro(ComponentsMask, ComponentsMaskType);
+  itkGetConstReferenceMacro(ComponentsMask, ComponentsMaskType);
+
+protected:
+  SplitComponentsImageFilter();
+  ~SplitComponentsImageFilter() override = default;
+
+  /** Do not allocate outputs that we will not populate. */
+  void
+  AllocateOutputs() override;
+
+  void
+  DynamicThreadedGenerateData(const OutputRegionType & outputRegion) override;
+
+private:
+  ComponentsMaskType m_ComponentsMask;
+};
+
+} // end namespace itk
+
+#ifndef ITK_MANUAL_INSTANTIATION
+#  include "itkSplitComponentsImageFilter.hxx"
+#endif
+
+#endif