feat(postprocess): add MEBin post-processing method

[StarPlatinum7]

📝 Description

This pull request introduces support for the MEBIN post-processing method within the Anomalib framework. The implementation includes a new post-processing algorithm that ​​mitigates false positives and false negatives in the binarization results by identifying the threshold interval where connected components remains stable.​ This strategy is proposed in AnomalyNCD (CVPR2025).

✨ Changes

• Added new post-processing method: src/anomalib/post_processing/mebin_post_processor.py
• Added new threshold method: src/anomalib/metrics/threshold/mebin.py
• Updated necessary __init__.py files to expose new modules

Example Usage

Here's how to use the mebin_post_porocessor in your projects:

from anomalib.data import MVTecAD
from anomalib.models import Patchcore
from anomalib.engine import Engine
from anomalib.post_processing import MEBinPostProcessor

# Initialize the datamodule, model and engine
datamodule = MVTecAD(
    category='bottle', # category in mvtec dataset
    root = "./data/mvtec_anomaly_detection", # path where dataset is stored
    train_batch_size = 32,
    eval_batch_size = 32,
)

engine = Engine()

model = Patchcore(
    post_processor=MEBinPostProcessor(
        sample_rate=4,
        min_interval_len=4,
        erode=True
    )
)

# Train the model
engine.train(datamodule=datamodule, model=model)

Select what type of change your PR is:

• 🚀 New feature (non-breaking change which adds functionality)
• 🐞 Bug fix (non-breaking change which fixes an issue)
• 🔄 Refactor (non-breaking change which refactors the code base)
• ⚡ Performance improvements
• 🎨 Style changes (code style/formatting)
• 🧪 Tests (adding/modifying tests)
• 📚 Documentation update
• 📦 Build system changes
• 🚧 CI/CD configuration
• 🔧 Chore (general maintenance)
• 🔒 Security update
• 💥 Breaking change (fix or feature that would cause existing functionality to not work as expected)

✅ Checklist

Before you submit your pull request, please make sure you have completed the following steps:

• 📚 I have made the necessary updates to the documentation (if applicable).
• 🧪 I have written tests that support my changes and prove that my fix is effective or my feature works (if applicable).
• 🏷️ My PR title follows conventional commit format.

For more information about code review checklists, see the Code Review Checklist.

[codecov-commenter]

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Codecov Report

❌ Patch coverage is 29.72973% with 78 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
src/anomalib/metrics/threshold/mebin.py	13.04%	60 Missing ⚠️
...c/anomalib/post_processing/mebin_post_processor.py	51.35%	18 Missing ⚠️

📢 Thoughts on this report? Let us know!

[rajeshgangireddy]

Hi, Thanks for the addition of this post processor.
Apologies for somehow missing to review it.
I have now left. some comments.

[rajeshgangireddy]

Please add a link to the AnomalyNCD paper as reference.

[rajeshgangireddy]

Can you add the type annotation for function arguments and returns.

[rajeshgangireddy]

There is a circular import error when running this test.
E ImportError: cannot import name 'PostProcessor' from partially initialized module 'anomalib.post_processing' (most likely due to a circular import) (/anomalib/src/anomalib/post_processing/__init__.py)

[rajeshgangireddy]

To avoid circular import, I think this should work:

Suggested change

	from anomalib.post_processing import PostProcessor
	from .post_processor import PostProcessor

[rajeshgangireddy]

I have opened a new PR with your commits + my suggestions here : #3030 (that way your contributions are counted).

I will close this PR now, if you don't mind.