Style Transfer

Style transfer is the task of producing a pastiche image 'p' that shares the content of a content image 'c' and the style of a style image 's'. This code implements the paper "A Learned Representation for Artistic Style":

A Learned Representation for Artistic Style. Vincent Dumoulin, Jon Shlens, Manjunath Kudlur.

Setup

Whether you want to stylize an image with one of our pre-trained models or train your own model, you need to set up your enviroment, install requirements.txt.

Jupyter notebook

There is a Jupyter notebook Image_Stylization.ipynb showing how to apply style transfer from a trained model.

Stylizing an Image

First, download one of our pre-trained models to /checkpoints:

• Monet
• Varied

(You can also train your own model, but if you're just getting started we recommend using a pre-trained model first.)

Then, run the following command:

python image_stylization_transform.py \
      --num_styles=<NUMBER_OF_STYLES> \
      --checkpoint=/path/to/model.ckpt \
      --input_image=/path/to/image.jpg \
      --which_styles="[0,1,2,5,14]" \
      --output_dir=/tmp/image_stylization/output \
      --output_basename="stylized"

You'll have to specify the correct number of styles for the model you're using. For the Monet model this is 10 and for the varied model this is 32. The which_styles argument should be a Python list of integer style indices.

which_styles can also be used to specify a linear combination of styles to combine in a single image. Use a Python dictionary that maps the style index to the weights for each style. If the style index is unspecified then it will have a zero weight. Note that the weights are not normalized.

Here's an example that produces a stylization that is an average of all of the monet styles.

python image_stylization_transform.py \
      --num_styles=10 \
      --checkpoint=/checkpoints/multistyle-pastiche-generator-monet.ckpt \
      --input_image=/evaluation_images/benjamin_harrison.jpg \
      --which_styles="{0:0.1,1:0.1,2:0.1,3:0.1,4:0.1,5:0.1,6:0.1,7:0.1,8:0.1,9:0.1}" \
      --output_dir=/tmp/image_stylization/output \
      --output_basename="all_monet_styles"

Training a Model

To train your own model, you'll need three things:

1. A directory of images to use as styles.
2. A trained VGG model checkpoint.
3. The ImageNet dataset. Instructions for downloading the dataset can be found here.

First, you need to prepare your style images:

$ image_stylization_create_dataset \
      --vgg_checkpoint=/path/to/vgg_16.ckpt \
      --style_files=/path/to/style/images/*.jpg \
      --output_file=/tmp/image_stylization/style_images.tfrecord

Then, to train a model:

$ image_stylization_train \
      --train_dir=/tmp/image_stylization/run1/train
      --style_dataset_file=/tmp/image_stylization/style_images.tfrecord \
      --num_styles=<NUMBER_OF_STYLES> \
      --vgg_checkpoint=/path/to/vgg_16.ckpt \
      --imagenet_data_dir=/path/to/imagenet-2012-tfrecord

To evaluate the model:

$ image_stylization_evaluate \
      --style_dataset_file=/tmp/image_stylization/style_images.tfrecord \
      --train_dir=/tmp/image_stylization/run1/train \
      --eval_dir=/tmp/image_stylization/run1/eval \
      --num_styles=<NUMBER_OF_STYLES> \
      --vgg_checkpoint=/path/to/vgg_16.ckpt \
      --imagenet_data_dir=/path/to/imagenet-2012-tfrecord \
      --style_grid

You can also finetune a pre-trained model for new styles:

$ image_stylization_finetune \
      --checkpoint=/path/to/model.ckpt \
      --train_dir=/tmp/image_stylization/run2/train
      --style_dataset_file=/tmp/image_stylization/style_images.tfrecord \
      --num_styles=<NUMBER_OF_STYLES> \
      --vgg_checkpoint=/path/to/vgg_16.ckpt \
      --imagenet_data_dir=/path/to/imagenet-2012-tfrecord

References

• Image Stylization: A "Multistyle Pastiche Generator" that generates artistics representations of photographs. Described in A Learned Representation For Artistic Style.