Fix Automatic Download of Pretrained Weights in DETR

[AnugunjNaman]

What does this PR do?

Fixes #15764

[HuggingFaceDocBuilderDev]

The documentation is not available anymore as the PR was closed or merged.

[AnugunjNaman]

@NielsRogge

[NielsRogge]

I don't think this makes sense, cause it will load pre-trained weights anyway.

A better code example (in my opinion) would be:

# randomly initialize a DETR model with pre-trained ResNet weights
config = DetrConfig()
model = DetrModel(config)

# randomly initialize a DETR model (with randomly initialized ResNet)
config = DetrConfig(use_pretrained_backbone=False)
model = DetrModel(config)

[AnugunjNaman]

@NielsRogge. Done. Works like you asked.

[NielsRogge]

Thanks for adding! We could perhaps add a small code example snippet in detr.mdx.

[AnugunjNaman]

@NielsRogge Any Update here?

[NielsRogge]

Suggested change

	from transformers import DetrConfig
	Option 1: instantiate DETR with pre-trained weights for entire model
	model = DetrForObjectDetection.from_pretrained("facebook/resnet-50")
	Option 2: instantiate DETR with randomly initialized weights for Transformer, but pre-trained weights for backbone
	config = DetrConfig()
	model = DetrForObjectDetection(config)
	Option 3: instantiate DETR with randomly initialized weights for backbone + Transformer
	config = DetrConfig(use_pretrained_backbone=False)
	model = DetrForObjectDetection(config)
	```
	from transformers import DetrConfig
	Option 1: instantiate DETR with pre-trained weights for entire model
	model = DetrForObjectDetection.from_pretrained("facebook/resnet-50")
	Option 2: instantiate DETR with randomly initialized weights for Transformer, but pre-trained weights for backbone
	config = DetrConfig()
	model = DetrForObjectDetection(config)
	Option 3: instantiate DETR with randomly initialized weights for backbone + Transformer
	config = DetrConfig(use_pretrained_backbone=False)
	model = DetrForObjectDetection(config)
	```

This won't properly render if you don't add the code statements.

[AnugunjNaman]

The black command failed when added python after `. Unclear how to proceed here in that case.

[NielsRogge]

Oh I think you need to do ```python for the first statement

[AnugunjNaman]

Did exactly that 66eae21 The circle ci failed

[NielsRogge]

See TAPAS as an example: https://raw.githubusercontent.com/huggingface/transformers/main/docs/source/en/model_doc/tapas.mdx

[sgugger]

Thanks for your contribution!