ANTsX/ANTs v2.6.0 on GitHub

This version is built with ITK 5.4.3.

Registration

Improvements to "syn only" transforms in antsRegistrationSyN*.sh scripts: these scripts now assume an identity initial transform, rather than doing a center-of-mass alignment by default. This better serves the usual use case for these kinds of transforms, either correcting nonlinear distortions in images from the same session, or doing nonlinear registration on images that have already been rigidly aligned.
The default CC radius and update step size in antsRegistrationSyN*.sh` have changed. Based on evaluations by @ntustison, a CC radius of 2 voxels is preferable to 4. The default step size of 0.1 in SyN registration has been increased to 0.2. Both of these can still be controlled by the user on the command line.
Histogram matching has been turned off by default in antsCorticalThickness.sh and the antsMultivariateTemplateConstruction*.sh scripts. It was already off by default in antsRegistrationSyN*.sh. An improved histogram matching function has been added to ANTsPy. If histogram matching is required, we recommend doing it as a preprocessing step so that it can be checked and done with the appropriate masks.
Composite transforms can now be written directly from antsApplyTransforms, without having to call CompositeTransformUtil.
An optimizer bug that could lead to unpredictable and suboptimal results in antsAI has been fixed.

Remove median computation for scalar images in LabelGeometryMeasures, because the filter uses a median approximation that can be inaccurate for some data (eg, statistical maps).
A very longstanding bug in CreateTiledMosaic is fixed: it will now output a tiled image without an RGB overlay. The overlay was supposed to be optional but was in fact required.
Handle windows newlines (used in Python CSV files on all platforms) in template construction input - this avoids confusing errors when passing CSV files as input to the template scripts.

CentOS 7 binaries are back, Ubuntu 20.04 moved to docker build.

Thanks to all contributors of code, bug reports, test data, and other help.

ENH: identity init transform for (bspline)syn-only by @cookpa in #1817
ENH: Make COM translation consistent with antsRegistration by @cookpa in #1821
ENH: Enhanced error checking by @cookpa in #1822
ENH: Change radius and gradient step defaults. by @ntustison in #1829
STYLE: Add itkVirtualGetNameOfClassMacro + itkOverrideGetNameOfClassMacro by @hjmjohnson in #1832
replace itkstaticconstmacro with constexpr by @hjmjohnson in #1833
ENH: Update default gradient step, turn off histogram matching by @cookpa in #1831
ENH: Check dimensionality of input warp fields. by @cookpa in #1835
DOC: Link to conda forge by @cookpa in #1837
ENH: use prefix of 1st param from --output for --write-interval-volumes by @mathdugre in #1838
Write composite transforms from antsApplyTransforms by @cookpa in #1839
ENH: use prefix from --output for --write-interval-volumes by @mathdugre in #1840
DOC: Better usage by @cookpa in #1841
ENH: Strip carriage returns from template input by @cookpa in #1845
CI: Move ubuntu 20.04 to Docker, revive Centos7 by @cookpa in #1846
ENH: Update ITK tag. by @ntustison in #1847
BUG: CreateTiledMosaic would not write images without an RGB overlay by @cookpa in #1849
ENH: Remove static output stream that was causing problems with ANTsPy by @cookpa in #1851
Label geometry histogram by @cookpa in #1854
BUG: Set scales estimator for antsAI by @cookpa in #1861
ENH: Update itk release by @cookpa in #1865

Full Changelog: v2.5.4...v2.6.0