Problems with SmallestMaxSize and LongestMaxSize

[antoniRodriguez]

• Albumentations installed via pip (version 2.0.0)
• Python 3.12.8

I encountered an issue when trying to use the max_size_hw parameter in A.LongestMaxSize within Albumentations. According to the documentation and the source code, it seems possible to specify max_size_hw to enforce maximum height and width constraints while maintaining the aspect ratio. However, when I attempt to use it, I receive the following error:

Code:

import albumentations as A

height, width = 250, 500
fill_value = 128

transform = A.Compose([
    A.LongestMaxSize(max_size_hw=(height, width)),
    A.PadIfNeeded(min_height=height, min_width=width, fill_value=fill_value),
])

Error:

Traceback (most recent call last):
  File "<placeholder_path>/venv/Lib/site-packages/albumentations/core/validation.py", line 35, in custom_init
    config = dct["InitSchema"](**full_kwargs)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<placeholder_path>/venv/Lib/site-packages/pydantic/main.py", line 214, in __init__
    validated_self = self.__pydantic_validator__.validate_python(data, self_instance=self)
                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
pydantic_core._pydantic_core.ValidationError: 1 validation error for InitSchema
  Value error, Only one of max_size or max_size_hw should be specified [type=value_error, input_value={'max_size_hw': (250, 500...terpolation': 0, 'p': 1}, input_type=dict]
    For further information visit https://errors.pydantic.dev/2.10/v/value_error

What I Tried:

• Ensured that I didn’t specify both max_size and max_size_hw in the LongestMaxSize transform.
• Checked the documentation and source code for A.LongestMaxSize to confirm that max_size_hw is a valid parameter.

Expected Behavior:

I expected the LongestMaxSize transform to resize the image such that both the height and width fit within the specified constraints (250, 500) while maintaining the aspect ratio.

Actual Behavior:

The error suggests that max_size_hw cannot be used in this way, even though the source code and documentation indicate otherwise.

Question:

Is there a specific way to use max_size_hw in LongestMaxSize? Or is this a bug in the current implementation?

[ternaus]

Thank you, fixed

[antoniRodriguez]

Thank you @ternaus!🎉