Feature request: add new option to save images locally

It would be nice if there is option (e.g. ``SAVE_IMAGES``) to save images locally.

- Basic: save all the images in a folder (specified by the user).
- Advance: provider an entrance to the let the user decide params in ````. This can be done by passing a user defined function: (param1, param2) -> (label, src). Then the user can decide for himself how to save the images (in the function).