Motivation

Multiple input size training like SDXL and NovelAI Aspect Ratio Bucketing.

Use cases (Optional)

dict(type='MultiAspectRatioResizeCenterCrop',
         sizes=[
             [640, 1536], [768, 1344], [832, 1216], [896, 1152],
             [1024, 1024], [1152, 896], [1216, 832], [1344, 768], [1536, 640]
             ],
         interpolation='bilinear'),



sampler=dict(type='DefaultSampler', shuffle=True),
batch_sampler=dict(type='AspectRatioBatchSampler'),

Checklist

Before PR:

• Pre-commit or other linting tools are used to fix the potential lint issues.
• Bug fixes are fully covered by unit tests, the case that causes the bug should be added in the unit tests.
• The modification is covered by complete unit tests. If not, please add more unit test to ensure the correctness.
• The documentation has been modified accordingly, like docstring or example tutorials.