PERF: Upgrade elastix to 2026-05-15 (faster AfterThreadedComputePDFs)

[N-Dekker]

Included elastix pull requests:

• PERF: Use ImageBufferRange in AfterThreadedComputePDFs SuperElastix/elastix#1440
• ENH: Print a warning for each unused parameter of the ParameterMap SuperElastix/elastix#1431

All included new commits:

SuperElastix/elastix@5.3.1...77c726a

[N-Dekker]

Just re-ran the original benchmark from Nicolas Chiaruttini (@NicoKiaru) at https://discourse.itk.org/t/8x-slower-registration-with-itk-elastix-python-api-vs-elastix-cli-minimal-reproducible-example/7736/1 (including the use of the unsupported "NumberOfThreads" parameter). At "my" LKEB/LUMC pc (AMD Threadripper, 32-Cores, 4 GHz, 64 logical processors), Windows 11, using Python 3.13.

Command-line arguments: --fixed blobs.tif --moving blobs-rot15deg.tif --runs 3 --elastix D:\X\Bin\E\elastix-5.3.1-windows\elastix.exe

Output with the latest itk-elastix release (0.25.3):

--- Run 1/3 (warm-up) ---
  [CLI]     2.01s  transform exists: True
  [itk-API] 36.50s  transform exists: True

--- Run 2/3 ---
  [CLI]     1.59s  transform exists: True
  [itk-API] 36.96s  transform exists: True

--- Run 3/3 ---
  [CLI]     2.06s  transform exists: True
  [itk-API] 35.73s  transform exists: True

Run            CLI (s)     itk-API (s)  ratio (itk/cli)
-------------------------------------------------------
*1               2.011          36.501          18.15x
 2               1.592          36.959          23.21x
 3               2.064          35.729          17.31x

Steady-state avg CLI     (runs 2+): 1.828s
Steady-state avg itk-API (runs 2+): 36.344s
Steady-state ratio (itk/cli): 19.88x

Output with the WindowsWheel311 from this pull request:

--- Run 1/3 (warm-up) ---
  [CLI]     3.43s  transform exists: True
  [itk-API] 6.93s  transform exists: True

--- Run 2/3 ---
  [CLI]     2.03s  transform exists: True
  [itk-API] 6.92s  transform exists: True

--- Run 3/3 ---
  [CLI]     2.12s  transform exists: True
  [itk-API] 6.97s  transform exists: True

Run            CLI (s)     itk-API (s)  ratio (itk/cli)
-------------------------------------------------------
*1               3.430           6.925           2.02x
 2               2.032           6.921           3.41x
 3               2.118           6.970           3.29x

Steady-state avg CLI     (runs 2+): 2.075s
Steady-state avg itk-API (runs 2+): 6.946s
Steady-state ratio (itk/cli): 3.35x

Conclusion: this pull request yields a major performance improvement. However, with this particular benchmark, the CLI (elastix.exe) still remains faster than itk-elastix. To be continued...!

P.S. With this pull request, the "elastix.log" created by itk-elastix has a warning, saying:

WARNING: 5 unused parameter(s) found!
  Unused parameter: AutomaticScalesEstimation
  Unused parameter: AutomaticTransformInitialization
  Unused parameter: AutomaticTransformInitializationMethod
  Unused parameter: ErodeMask
  Unused parameter: NumberOfThreads

So with this pull request it should be easier for users to find out that "NumberOfThreads" is not supported.