GAN Pokemon

I will use this project to learn how to train GAN's, how they work and apply it on Pokemon data to try and create new fun forms of pokemon.
There are a few similar projects on Github that inspired me :

• https://github.com/kvpratama/gan/tree/master/pokemon
• https://github.com/moxiegushi/pokeGAN

Pokemon GAN

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I used a pytorch implementation for the dataloading, model and training. For that i used an already existing one that i found here, and reworked it to fit my needs. I also used the tips and tricks from this github. The goal is to smooth the training of the model and improve it's stability.

The model is able to create blobs of color with forms that could ressemble animal/pokemon forms, but no details (no eyes, nose etc...).
Such as those :

as you can see, these are not super cool new pokemons yet, but this project is still in it's infancy.

Model & Backbone

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DCGAN

Basically, the generator is a CNN that is trained to turn a tensor of random (gaussian) noise into an image, and the discriminator is also a CNN that is trained to differentiate between real images and fake created by the generator. (I put a link to the paper in the references down below)
The particularity of GAN's such as this one is that in the case of creating new pokemons is that there isn't a real benchmark to tell you when the model is good or not, it's good when it's able to create images that you find good enough.

SNGAN

Spectral Normalization is a method used to help stabilize the training process of the discriminator.
I linked the paper below you'll find more information.

Code

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Prerequisites

python -m pip install -r requirements.txt

Train

python -m run 
--model=DCGAN 
--backbone=CONVNET 
--loss=BCE 
--run_note=NAME_OF_RUN

• model : DCGAN or SNGAN
• backbone : CONVNET or RESNET
• loss : BCE, LB_CE (Label Smoothing Cross entropy) or WGAN
• run_note : a name for the training run.

Evaluate

Evaluation function can be used on a specified checkpoint to generate a batch of fake images from you checkpoint model in a result/ folder
You must specify the model used in your checkpoint and a path to the checkpoint file :

python -m inference 
--model=DCGAN 
--backbone=CONVNET 
--path=checkpoint/checkpoint_name.pt
--note=NAME_OF_EVAL

Tensorboard

I use tensorboard to save some informations about models trained :

• Save G and D loss after each epoch
• Save a grid of fake images every few epochs

The results are in a runs/run_note folder :

tensorboard --logdir=runs/NAME_OF_RUN

Next steps

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The next steps for this project include :

• Changing the model (image size, more performant model)
• Improving the dataset (Cleaning images that are too similar, adding new images)
• Look into SN-GAN and SAGAN for next implementation

Reference

[1] Unsupervised Representation Learning with Deep Convolutional Generative Adversarial Networks
[2] Generative Adversarial Networks
[3] Wasserstein GAN
[4] Improved Training of Wasserstein GANs
[5] Spectral Normalization for Generative Adversarial Networks