Learning to Draw: Emergent Communication through Sketching

This is the official code for the paper "Learning to Draw: Emergent Communication through Sketching".

ArXiv • Papers With Code • Getting Started • Game setups • Model setup • Datasets

About

We demonstrate that it is possible for a communication channel based on line drawing to emerge between agents playing a visual referential communication game. Furthermore we show that with a simple additional self-supervised loss that the drawings the agent produces are interpretable by humans.

Getting started

You'll need to install the required dependencies listed in requirements.txt. This includes installing the differentiable rasteriser from the DifferentiableSketching repository, and the source version of https://github.com/pytorchbearer/torchbearer:

pip install git+https://github.com/jonhare/DifferentiableSketching.git
pip install git+https://github.com/pytorchbearer/torchbearer.git
pip install -r requirements.txt

Once the dependencies are installed, you can run the commgame.py script to train and test models:

python commgame.py train [args]
python commgame.py test [args]

For example, to train a pair of agents on the original game using the STL10 dataset (which will be downloaded if required), you would run:

python commgame.py train --dataset STL10 --output stl10-original-model --sigma2 5e-4 --nlines 20 --learning-rate 0.0001 --imagenet-weights --freeze-vgg --imagenet-norm --epochs 250 --invert --batch-size 100

The options --sigma2 and --nlines control the thickness and number of lines respectively. --imagenet-weights uses the standard pretrained imagenet vgg16 weights (use --sin-weights for stylized imagenet weights). Finally, --freeze-vgg freezes the backbone CNN, --imagenet-norm specifies to apply the imagenet normalisation to images (this should be used when using either imagenet or stylized imagenet weights), and --invert draws black strokes on a white canvas.

The training scripts compute a running communication rate in addition to loss and this is displayed as training progresses. After each epoch a validation pass is performed and images of the sketches and sender inputs and receiver targets are saved to the output directory along with a model snapshot. The output directory also contains a log file with the training and validation statistics per epoch.

Example commands to run the experiments in the paper are given in commands.md

Further details on commandline arguments are given below.

Game setups

All the setups involve a referential game where the reciever tries to select the "correct" image from a pool on the basis of a "sketch" provided by the sender. The primary measure of success is the communication rate. The different command line arguments to control the different game variants are listed in the following subsections:

Havrylov and Titov's Original Game Setup

Sender sees one image; Reciever sees many, where one is exactly the same as sender.

Number of reciever images (target + distractors) is controlled by the batch-size. Number of sender images per iteration can also be controlled for completeness, but defaults to the same as batch size (e.g. each forward pass with a batch plays all possible game combinations using each of the images as a target).

arguments:
--batch-size
[--sender-images-per-iter]

Object-oriented Game Setup (same)

Sender sees one image; Reciever sees many, where one is exactly the same as sender and the others are all of different classes.

arguments:
--object-oriented same
[--num-targets]
[--sender-images-per-iter]

Object-oriented Game Setup (different)

Sender sees one image; Reciever sees many, each of different classes; one of the images is the same class as the sender, but is a completely different image).

arguments:
--object-oriented different 
[--num-targets]
[--sender-images-per-iter]
[--random-transform-sender]

Model setup

Sender

The "sender" consists of a backbone VGG16 CNN which translates the input image into a latent vector and a "decoder" with an MLP that projects the latent representation from the backbone to a set of drawing commands that are differentiably rendered into an image which is sent to the "reciever".

The backbone can optionally be initialised with pretrained weight and also optionally frozen (except for the final linear projection). The backbone, including linear projection can be shared between sender and reciever (default) or separate (--separate_encoders).

arguments:
[--freeze-vgg]
[--imagenet-weights --imagenet-norm] 
[--sin-weights --imagenet-norm] 
[--separate_encoders]

Receiver

The "receiver" consists of a backbone CNN which is used to convert visual inputs (both the images in the pool and the sketch) into a latent vector which is then transformed into a different latent representation by an MLP. These projected latent vectors are used for prediction and in the loss as described below.

The actual backbone CNN model architecture will be the same as the sender's. The backbone can optionally share parameters with the "sender" agent. Alternatively it can be initialised with pre-trained weights, and also optionally frozen.

arguments:
[--freeze-vgg]
[--imagenet-weights --imagenet-norm]
[--separate_encoders]

Datasets

• MNIST
• CIFAR-10 / CIFAR-100
• TinyImageNet
• CelebA (--image-size to control size; default 64px)
• STL-10
• Caltech101 (training data is balanced by supersampling with augmentation)

Datasets will be downloaded to the dataset root directory (default ./data) as required.

arguments: 
--dataset {CIFAR10,CelebA,MNIST,STL10,TinyImageNet,Caltech101}  
[--dataset-root]

Citation

If you find this repository useful for your research, please cite our paper using the following.

  @@inproceedings{
  mihai2021learning,
  title={Learning to Draw: Emergent Communication through Sketching},
  author={Daniela Mihai and Jonathon Hare},
  booktitle={Thirty-Fifth Conference on Neural Information Processing Systems},
  year={2021},
  url={https://openreview.net/forum?id=YIyYkoJX2eA}
  }