alobugdays/23-pad-accepts-multiple-argument

[tflahaul]

• First addition of issue Padding frame to a multiple of an integer n #23 : being able to pad the tensor to the next multiple of multiple
• unittest

Minimal example

>>> x = aloscene.Frame(torch.rand(1, 10, 10), names=('C', 'H', 'W'))
>>> x.pad(multiple=8).shape
torch.Size([1, 16, 16])
>>> x.pad(multiple=10).shape
torch.Size([1, 10, 10])
>>> x.pad(multiple=32).shape
torch.Size([1, 32, 32])

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This pull request includes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update