# Instagram ResNeXt WSL
A **ResNeXt** repeats a [building block](https://paperswithcode.com/method/resnext-block) that aggregates a set of transformations with the same topology. Compared to a [ResNet](https://paperswithcode.com/method/resnet), it exposes a new dimension, *cardinality* (the size of the set of transformations) $C$, as an essential factor in addition to the dimensions of depth and width.
This model was trained on billions of Instagram images using thousands of distinct hashtags as labels exhibit excellent transfer learning performance.
Please note the CC-BY-NC 4.0 license on theses weights, non-commercial use only.
## How do I use this model on an image?
To load a pretrained model:
```py
>>> import timm
>>> model = timm.create_model('ig_resnext101_32x16d', pretrained=True)
>>> model.eval()
```
To load and preprocess the image:
```py
>>> import urllib
>>> from PIL import Image
>>> from timm.data import resolve_data_config
>>> from timm.data.transforms_factory import create_transform
>>> config = resolve_data_config({}, model=model)
>>> transform = create_transform(**config)
>>> url, filename = ("https://github.com/pytorch/hub/raw/master/images/dog.jpg", "dog.jpg")
>>> urllib.request.urlretrieve(url, filename)
>>> img = Image.open(filename).convert('RGB')
>>> tensor = transform(img).unsqueeze(0) # transform and add batch dimension
```
To get the model predictions:
```py
>>> import torch
>>> with torch.no_grad():
... out = model(tensor)
>>> probabilities = torch.nn.functional.softmax(out[0], dim=0)
>>> print(probabilities.shape)
>>> # prints: torch.Size([1000])
```
To get the top-5 predictions class names:
```py
>>> # Get imagenet class mappings
>>> url, filename = ("https://raw.githubusercontent.com/pytorch/hub/master/imagenet_classes.txt", "imagenet_classes.txt")
>>> urllib.request.urlretrieve(url, filename)
>>> with open("imagenet_classes.txt", "r") as f:
... categories = [s.strip() for s in f.readlines()]
>>> # Print top categories per image
>>> top5_prob, top5_catid = torch.topk(probabilities, 5)
>>> for i in range(top5_prob.size(0)):
... print(categories[top5_catid[i]], top5_prob[i].item())
>>> # prints class names and probabilities like:
>>> # [('Samoyed', 0.6425196528434753), ('Pomeranian', 0.04062102362513542), ('keeshond', 0.03186424449086189), ('white wolf', 0.01739676296710968), ('Eskimo dog', 0.011717947199940681)]
```
Replace the model name with the variant you want to use, e.g. `ig_resnext101_32x16d`. You can find the IDs in the model summaries at the top of this page.
To extract image features with this model, follow the [timm feature extraction examples](../feature_extraction), just change the name of the model you want to use.
## How do I finetune this model?
You can finetune any of the pre-trained models just by changing the classifier (the last layer).
```py
>>> model = timm.create_model('ig_resnext101_32x16d', pretrained=True, num_classes=NUM_FINETUNE_CLASSES)
```
To finetune on your own dataset, you have to write a training loop or adapt [timm's training
script](https://github.com/rwightman/pytorch-image-models/blob/master/train.py) to use your dataset.
## How do I train this model?
You can follow the [timm recipe scripts](../scripts) for training a new model afresh.
## Citation
```BibTeX
@misc{mahajan2018exploring,
title={Exploring the Limits of Weakly Supervised Pretraining},
author={Dhruv Mahajan and Ross Girshick and Vignesh Ramanathan and Kaiming He and Manohar Paluri and Yixuan Li and Ashwin Bharambe and Laurens van der Maaten},
year={2018},
eprint={1805.00932},
archivePrefix={arXiv},
primaryClass={cs.CV}
}
```
<!--
Type: model-index
Collections:
- Name: IG ResNeXt
Paper:
Title: Exploring the Limits of Weakly Supervised Pretraining
URL: https://paperswithcode.com/paper/exploring-the-limits-of-weakly-supervised
Models:
- Name: ig_resnext101_32x16d
In Collection: IG ResNeXt
Metadata:
FLOPs: 46623691776
Parameters: 194030000
File Size: 777518664
Architecture:
- 1x1 Convolution
- Batch Normalization
- Convolution
- Global Average Pooling
- Grouped Convolution
- Max Pooling
- ReLU
- ResNeXt Block
- Residual Connection
- Softmax
Tasks:
- Image Classification
Training Techniques:
- Nesterov Accelerated Gradient
- Weight Decay
Training Data:
- IG-3.5B-17k
- ImageNet
Training Resources: 336x GPUs
ID: ig_resnext101_32x16d
Epochs: 100
Layers: 101
Crop Pct: '0.875'
Momentum: 0.9
Batch Size: 8064
Image Size: '224'
Weight Decay: 0.001
Interpolation: bilinear
Code: https://github.com/rwightman/pytorch-image-models/blob/d8e69206be253892b2956341fea09fdebfaae4e3/timm/models/resnet.py#L874
Weights: https://download.pytorch.org/models/ig_resnext101_32x16-c6f796b0.pth
Results:
- Task: Image Classification
Dataset: ImageNet
Metrics:
Top 1 Accuracy: 84.16%
Top 5 Accuracy: 97.19%
- Name: ig_resnext101_32x32d
In Collection: IG ResNeXt
Metadata:
FLOPs: 112225170432
Parameters: 468530000
File Size: 1876573776
Architecture:
- 1x1 Convolution
- Batch Normalization
- Convolution
- Global Average Pooling
- Grouped Convolution
- Max Pooling
- ReLU
- ResNeXt Block
- Residual Connection
- Softmax
Tasks:
- Image Classification
Training Techniques:
- Nesterov Accelerated Gradient
- Weight Decay
Training Data:
- IG-3.5B-17k
- ImageNet
Training Resources: 336x GPUs
ID: ig_resnext101_32x32d
Epochs: 100
Layers: 101
Crop Pct: '0.875'
Momentum: 0.9
Batch Size: 8064
Image Size: '224'
Weight Decay: 0.001
Interpolation: bilinear
Minibatch Size: 8064
Code: https://github.com/rwightman/pytorch-image-models/blob/d8e69206be253892b2956341fea09fdebfaae4e3/timm/models/resnet.py#L885
Weights: https://download.pytorch.org/models/ig_resnext101_32x32-e4b90b00.pth
Results:
- Task: Image Classification
Dataset: ImageNet
Metrics:
Top 1 Accuracy: 85.09%
Top 5 Accuracy: 97.44%
- Name: ig_resnext101_32x48d
In Collection: IG ResNeXt
Metadata:
FLOPs: 197446554624
Parameters: 828410000
File Size: 3317136976
Architecture:
- 1x1 Convolution
- Batch Normalization
- Convolution
- Global Average Pooling
- Grouped Convolution
- Max Pooling
- ReLU
- ResNeXt Block
- Residual Connection
- Softmax
Tasks:
- Image Classification
Training Techniques:
- Nesterov Accelerated Gradient
- Weight Decay
Training Data:
- IG-3.5B-17k
- ImageNet
Training Resources: 336x GPUs
ID: ig_resnext101_32x48d
Epochs: 100
Layers: 101
Crop Pct: '0.875'
Momentum: 0.9
Batch Size: 8064
Image Size: '224'
Weight Decay: 0.001
Interpolation: bilinear
Code: https://github.com/rwightman/pytorch-image-models/blob/d8e69206be253892b2956341fea09fdebfaae4e3/timm/models/resnet.py#L896
Weights: https://download.pytorch.org/models/ig_resnext101_32x48-3e41cc8a.pth
Results:
- Task: Image Classification
Dataset: ImageNet
Metrics:
Top 1 Accuracy: 85.42%
Top 5 Accuracy: 97.58%
- Name: ig_resnext101_32x8d
In Collection: IG ResNeXt
Metadata:
FLOPs: 21180417024
Parameters: 88790000
File Size: 356056638
Architecture:
- 1x1 Convolution
- Batch Normalization
- Convolution
- Global Average Pooling
- Grouped Convolution
- Max Pooling
- ReLU
- ResNeXt Block
- Residual Connection
- Softmax
Tasks:
- Image Classification
Training Techniques:
- Nesterov Accelerated Gradient
- Weight Decay
Training Data:
- IG-3.5B-17k
- ImageNet
Training Resources: 336x GPUs
ID: ig_resnext101_32x8d
Epochs: 100
Layers: 101
Crop Pct: '0.875'
Momentum: 0.9
Batch Size: 8064
Image Size: '224'
Weight Decay: 0.001
Interpolation: bilinear
Code: https://github.com/rwightman/pytorch-image-models/blob/d8e69206be253892b2956341fea09fdebfaae4e3/timm/models/resnet.py#L863
Weights: https://download.pytorch.org/models/ig_resnext101_32x8-c38310e5.pth
Results:
- Task: Image Classification
Dataset: ImageNet
Metrics:
Top 1 Accuracy: 82.7%
Top 5 Accuracy: 96.64%
-->
