src/training/utils.py

import numpy as np
from functools import partial
from six.moves import map, zip


def multi_apply(func, *args, **kwargs):
    """Apply function to a list of arguments.
    Note:
        This function applies the ``func`` to multiple inputs and
        map the multiple outputs of the ``func`` into different
        list. Each list contains the same type of outputs corresponding
        to different inputs.
    Args:
        func (Function): A function that will be applied to a list of
            arguments
    Returns:
        tuple(list): A tuple containing multiple list, each list contains \
            a kind of returned results by the function
    """
    pfunc = partial(func, **kwargs) if kwargs else func
    map_results = map(pfunc, *args)
    return tuple(map(list, zip(*map_results)))


def mask2box(mask):
    ys, xs = np.where(mask)
    y0, y1 = ys.min(), ys.max()
    x0, x1 = xs.min(), xs.max()

    return x0, y0, x1, y1