Fast neural style trasnfer using Colab TPUs by TensorFlow/Keras.
You can output an image of 256x256 resolution in 3000 epoch in about 15 minutes.
Other parameters are both content loss = 0.025, style loss = 1.
Keras neural style transfer example (GPUs version)
https://github.com/keras-team/keras/blob/master/examples/neural_style_transfer.py