def get_filter_config(shape):
    """Returns a default Conv2D filter config (list) for a given image shape.

    Args:
        shape (Tuple[int]): The input (image) shape, e.g. (84,84,3).

    Returns:
        List[list]: The Conv2D filter configuration usable as `conv_filters`
            inside a model config dict.
    """
    shape = list(shape)
    filters_84x84 = [
        [16, [8, 8], 4],
        [32, [4, 4], 2],
        [256, [11, 11], 1],
    ]
    filters_42x42 = [
        [16, [4, 4], 2],
        [32, [4, 4], 2],
        [256, [11, 11], 1],
    ]
    if len(shape) == 3 and shape[:2] == [84, 84]:
        return filters_84x84
    elif len(shape) == 3 and shape[:2] == [42, 42]:
        return filters_42x42
    else:
        raise ValueError(
            "No default configuration for obs shape {}".format(shape) +
            ", you must specify `conv_filters` manually as a model option. "
            "Default configurations are only available for inputs of shape "
            "[42, 42, K] and [84, 84, K]. You may alternatively want "
            "to use a custom model or preprocessor.")