If you would like to apply a pre-trained model to a collection of input photos (without image pairs), please use --dataset_mode single and --model test options. For example, landscape painting - landscape photographs works much better than portrait painting - landscape photographs. For example, these might be pairs {label map, photo} or {bw image, color image}. A and B should each have their own subfolders train, val, test, etc.

To train a model on your own datasets, you need to create a data folder with two subdirectories trainA and trainB that contain images from domain A and B. For example, landscape painting - landscape photographs works much better than portrait painting - landscape photographs. A and B should each have their own subfolders train, val, test, etc. In /path/to/data/A/train, put training images in style A.