With VGG, it takes a long time to make good looking images. (-m vgg, -m vgg_chainer)
After downloading and using the vgg_chainer model for the first time, all subsequent uses will load the model very fast.(functionality available in chainer 1.19 and above).
It is possible to change from nin to vgg, vgg_chainer, googlenet or i2v. To do this, put the model file in the working directory, keeping the default file name.
Generate multiple images simultaneously
First, create a file called input.txt and list the input and output file names:
input0.png style0.png
input1.png style1.png
...
then, run chainer-gogh-multi.py:
python chainer-gogh-multi.py -i input.txt
The VGG model uses a lot of GPU memory, be careful!
About the parameters
--lr: learning rate. Increase this when the generation progress is slow.
--lam: increase to make the output image similar to the input, decrease to add more style.
alpha, beta: coefficients relating to the error propagated from each layer. They are hard coded for each model.
Advice
At the moment, using square images (e.g. 256x256) is best.