Add UperNet (#20648)

* First draft

* More improvements

* Add convnext backbone

* Add conversion script

* Add more improvements

* Comment out to_dict

* Add to_dict method

* Add default config

* Fix config

* Fix backbone

* Fix backbone some more

* Add docs, auto mapping, tests

* Fix some tests

* Fix more tests

* Fix more tests

* Add conversion script

* Improve conversion script

* Add support for getting reshaped undownsampled hidden states

* Fix forward pass

* Add print statements

* Comment out set_shift_and_window_size

* More improvements

* Correct downsampling layers conversion

* Fix style

* First draft

* Fix conversion script

* Remove config attribute

* Fix more tests

* Update READMEs

* Update ConvNextBackbone

* Fix ConvNext tests

* Align ConvNext with Swin

* Remove files

* Fix index

* Improve docs

* Add output_attentions to model forward

* Add backbone mixin, improve tests

* More improvements

* Update init_weights

* Fix interpolation of logits

* Add UperNetImageProcessor

* Improve image processor

* Fix image processor

* Remove print statements

* Remove script

* Update import

* Add image processor tests

* Remove print statements

* Fix test

* Add integration test

* Add convnext integration test

* Update docstring

* Fix README

* Simplify config

* Apply suggestions

* Improve docs

* Rename class

* Fix test_initialization

* Fix import

* Address review

* Fix confg

* Convert all checkpoints

* Fix default backbone

* Usage same processor as segformer

* Apply suggestions

* Fix init_weights, update conversion scripts

* Improve config

* Use Auto API instead of creating a new image processor

* Fix docs

* Add doctests

* Remove ResNetConfig dependency

* Add always_partition argument

* Fix rebaseé

* Improve docs

* Convert checkpoints

Co-authored-by: Niels Rogge <nielsrogge@Nielss-MacBook-Pro.local>
Co-authored-by: Niels Rogge <nielsrogge@Nielss-MBP.localdomain>

utils/documentation_tests.txt

@@ -179,6 +179,7 @@ src/transformers/models/trocr/modeling_trocr.py
 src/transformers/models/unispeech/configuration_unispeech.py
 src/transformers/models/unispeech/modeling_unispeech.py
 src/transformers/models/unispeech_sat/modeling_unispeech_sat.py
+src/transformers/models/upernet/modeling_upernet.py
 src/transformers/models/van/modeling_van.py
 src/transformers/models/videomae/modeling_videomae.py
 src/transformers/models/vilt/modeling_vilt.py