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Copyright 2021 The HuggingFace Team. All rights reserved. |
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Licensed under the Apache License, Version 2.0 (the "License"); |
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# Image Classification training examples |
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The following example showcases how to train/fine-tune `ViT` for image-classification using the JAX/Flax backend. |
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JAX/Flax allows you to trace pure functions and compile them into efficient, fused accelerator code on both GPU and TPU. |
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Models written in JAX/Flax are **immutable** and updated in a purely functional |
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way which enables simple and efficient model parallelism. |
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In this example we will train/fine-tune the model on the [imagenette](https://github.com/fastai/imagenette) dataset. |
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## Prepare the dataset |
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We will use the [imagenette](https://github.com/fastai/imagenette) dataset to train/fine-tune our model. Imagenette is a subset of 10 easily classified classes from Imagenet (tench, English springer, cassette player, chain saw, church, French horn, garbage truck, gas pump, golf ball, parachute). |
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### Download and extract the data. |
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```bash |
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wget https://s3.amazonaws.com/fast-ai-imageclas/imagenette2.tgz |
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tar -xvzf imagenette2.tgz |
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``` |
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This will create a `imagenette2` dir with two subdirectories `train` and `val` each with multiple subdirectories per class. The training script expects the following directory structure |
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```bash |
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root/dog/xxx.png |
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root/dog/xxy.png |
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root/dog/[...]/xxz.png |
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root/cat/123.png |
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root/cat/nsdf3.png |
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root/cat/[...]/asd932_.png |
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``` |
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## Train the model |
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Next we can run the example script to fine-tune the model: |
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```bash |
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python run_image_classification.py \ |
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--output_dir ./vit-base-patch16-imagenette \ |
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--model_name_or_path google/vit-base-patch16-224-in21k \ |
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--train_dir="imagenette2/train" \ |
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--validation_dir="imagenette2/val" \ |
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--num_train_epochs 5 \ |
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--learning_rate 1e-3 \ |
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--per_device_train_batch_size 128 --per_device_eval_batch_size 128 \ |
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--overwrite_output_dir \ |
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--preprocessing_num_workers 32 \ |
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--push_to_hub |
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``` |
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This should finish in ~7mins with 99% validation accuracy. |