Expose keepdim for torchgeo.transforms.indices

[MathiasBaumgartinger]

Summary

Currently, none of the indices expose their inherited property keepdim. For some cases this might be useful.

Rationale

Without the usage of keepdim=True on the augmentations, my CrossEntropyLoss fails with RuntimeError: only batches of spatial targets supported (3D tensors) but got targets of dimension: [batch_size, 1, H, W], because an additional dimension is added.

Implementation

Expose keepdim: bool=False in __init()__

Alternatives

No response

Additional information

No response

[adamjstewart]

I've always wondered why keepdim isn't True by default, I can't think of any reason I would ever want it to be False.

Instead of explicitly adding a keepdim parameter, I would instead add **kwargs to all transforms and pass it directly to super().__init__().

[MathiasBaumgartinger]

I agree, was quite flattered that some deep base augmentation class would for some reason add a completely unnecessary dimension. Anyway, some form of (by default keepdim=True) option and/or hint would be beneficial. Took me some time to debug that.

[adamjstewart]

Want to open a PR to add the kwargs forwarding? You could then show how to use keepdim in our Transforms tutorial.