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How transferable are features in deep neural networks?

This repository contains source code necessary to reproduce the results presented in the following paper:

@inproceedings{yosinski_2014_NIPS
  title={How transferable are features in deep neural networks?},
  author={Yosinski, Jason and Clune, Jeff and Bengio, Yoshua and Lipson, Hod},
  booktitle={Advances in Neural Information Processing Systems 27 (NIPS '14)},
  editor = {Z. Ghahramani and M. Welling and C. Cortes and N.D. Lawrence and K.Q. Weinberger},
  publisher = {Curran Associates, Inc.},
  pages = {3320--3328},
  year={2014}
}

The are four steps to using this codebase to reproduce the results in the paper.

Each is described below. Training results are also provided in the results directory for those just wishing to compare results to their own work without undertaking the arduous training process.

Assemble prerequisites

Several dependencies should be installed.

Create Datasets

1. Obtain ILSVRC 2012 dataset

The ImageNet Large Scale Visual Recognition Challenge (ILSVRC) 2012 dataset can be downloaded here (registration required).

2. Create derivative dataset splits

The necessary smaller derivative datasets (random halves, natural and man-made halves, and reduced volume versions) can be created from the raw ILSVRC12 dataset.

$ cd ilsvrc12
$ ./make_reduced_datasets.sh

The script will do most of the work, including setting random seeds to hopefully produce the exact same random splits used in the paper. Md5sums are listed for each dataset file at the bottom of make_reduced_datasets.sh, which can be used to verify the match. Results may vary on different platforms though, so don't worry too much if your sums don't match.

3. Convert datasets to databases

The datasets created above are so far just text files providing a list of image filenames and class ids. To train a Caffe model, they should be converted to a LevelDB or LMDB, one per dataset. See the Caffe ImageNet Tutorial for a more in depth look at this process.

First, edit create_all_leveldbs.sh and set the IMAGENET_DIR and CAFFE_TOOLS_DIR to point to the directories containing the ImageNet image files and compiled caffe tools (like convert_imageset.bin), respectively. Then run:

$ ./create_all_leveldbs.sh

This step takes a lot of space (and time), approximately 230 GB for the base training dataset, and on average 115 GB for each of the 10 split versions, for a total of about 1.5 TB. If this is prohibitive, you might consider using a different type of data layer type for Caffe that loads images directly from a single shared directory.

4. Compute the mean of each dataset

Again, edit the paths in the script to point to the appropriate locations, and then run:

$ ./create_all_means.sh

This just computes the mean of each dataset and saves it in the dataset directory. Means are subtracted from input images during training and inference.

Train models

A total of 163 networks were trained to produce the results in the paper. Many of these networks can be trained in parallel, but because weights are transferred from one network to another, some must be trained serially. In particular, all networks in the first block below must be trained before any in the second block can be trained. All networks within a block may be trained at the same time. The "whenever" block does not contain dependencies and can be trained any time.

Block: one
  half*       (10 nets)

Block: two
  transfer*   (140 nets)

Block: whenever
  netbase     (1 net)
  reduced-*   (12 nets)

To train a given network, change to its directory, copy (or symlink) the required caffe executable, and run the training procedure. This can be accomplished using the following commands, demonstrated for the half0A network:

$ cd results/half0A
$ cp /path/to/caffe/build/tools/caffe.bin .
$ ./caffe.bin train -solver imagenet_solver.prototxt

Repeat this process for all networks in block: one and block: whenever above. Once the networks in block: one are trained, train all the networks in block: two similarly. This time the command is slightly different, because we need to load the base network in order to fine-tune it on the target task. Here's an example for the transfer0A0A_1_1 network:

$ cd results/transfer0A0A_1_1
$ cp /path/to/caffe/build/tools/caffe.bin .
$ ./caffe.bin train -solver imagenet_solver.prototxt -weights basenet/caffe_imagenet_train_iter_450000

The basenet symlinks have been added to point to the appropriate base network, but the basenet/caffe_imagenet_train_iter_450000 file will not exist until the relevant block: one networks has been trained.

Training notes: while the above procedure should work if followed literally, because each network takes about 9.5 days to train (on a K20 GPU), it will be much faster to train networks in parallel in a cluster environment. To do so, create and submit jobs as appropriate for your system. You'll also want to ensure that the output of the training procedure is logged, either by piping to a file

$ ./caffe.bin train ... > log_file 2>&1

or via whatever logging facilities are supplied by your cluster or job manager setup.

Plot results

Once the networks are trained, the results can be plotted using the included IPython notebook plots/transfer_plots.ipynb. Start the IPython Notebook server:

$ cd plots
$ ipython notebook

Select the transfer_plots.ipynb notebook and execute the included code. Note that without modification, the code will load results from the cached log files included in this repository. If you've run your own training and wish to plot those log files, change the paths in the "Load all the data" section to point to your log files instead.

Shortcut: to skip all the work and just see the results, take a look at this notebook with cached plots.

Questions?

Please drop me a line if you have any questions!