Use Configs

Detectron2’s config system uses yaml and yacs. In addition to the basic operations that access and update a config, we provide the following extra functionalities:

  1. The config can have _BASE_: base.yaml field, which will load a base config first. Values in the base config will be overwritten in sub-configs, if there are any conflicts. We provided several base configs for standard model architectures.
  2. We provide config versioning, for backward compatibility. If your config file is versioned with a config line like VERSION: 2, detectron2 will still recognize it even if we rename some keys in the future.

Use Configs

Some basic usage of the CfgNode object is shown below:

from detectron2.config import get_cfg
cfg = get_cfg()    # obtain detectron2's default config
cfg.xxx = yyy      # add new configs for your own custom components
cfg.merge_from_file("my_cfg.yaml")   # load values from a file

cfg.merge_from_list(["MODEL.WEIGHTS", "weights.pth"])   # can also load values from a list of str

To see a list of available configs in detectron2, see Config References

Best Practice with Configs

  1. Treat the configs you write as “code”: avoid copying them or duplicating them; use “BASE” instead to share common parts between configs.
  2. Keep the configs you write simple: don’t include keys that do not affect the experimental setting.
  3. Keep a version number in your configs (or the base config), e.g., VERSION: 2, for backward compatibility. The builtin configs do not include version number because they are meant to be always up-to-date.
  4. Save a full config together with a trained model, and use it to run inference. This is more robust to changes that may happen to the config definition (e.g., if a default value changed).