build_template creates "temporary files" but doesn't remove them

[dyollb]

I was running build_template on the Calgary Campinas dataset and suddenly noticed my disk was full.

Describe the bug

Looking at the code, I see a for each image in the image_list, a registration with no outprefix is run. When outprefix is not set, a temporary file name is created using mktemp. The temporary files saved by the registration are not deleted.

To reproduce

Run with large dataset and compare the disk space before/after.

Expected behavior

I would expect that temporary registration results are deleted, unless a "working directory" is specified by a user. In this case it would be nice to save the registration files in a structured way, e.g.

• working dir
  • img000/outWarp.nii.gz, etc.
  • img001/outWarp.nii.gz, etc.
  • img002/outWarp.nii.gz, etc.

Screenshots

na

ANTsPy installation (please complete the following information):

• Hardware: PC

• OS: Windows

• System details
  • OS Name: Microsoft Windows 11 Enterprise
  • OS Version: 10.0.26100 N/A Build 26100
  • System Type: x64-based PC

• Sub-system: [ ]

• ANTsPy version: 0.5.4

• Installation type: pip

Additional context
Add any other context about the problem here. Many issues are specific to particular data
so please include example data if possible.

[dyollb]

the temp files produced and not cleaned up:

[dyollb]

proposed solution:

1. add argument output_dir=None to build_template
2. add helper function make_outprefix(k: int) -> str
3. call ants.registration with outprefix=make_outprefix(k)
4. at the end, if output_dir is None, delete work_dir

    work_dir = mktemp() if output_dir is None else output_dir

    def make_outprefix(k: int):
        os.makedirs(os.path.join(work_dir, f"img{k:04d}"), exist_ok=True)
        return os.path.join(work_dir, f"img{k:04d}", "out")

I am happy to submit a pull request.