crop white of an image

crop.py

# Source: https://www.kaggle.com/lopuhin/panda-2020-level-1-2


def crop_white(image: np.ndarray, value: int = 255) -> np.ndarray:
    assert image.shape[2] == 3
    assert image.dtype == np.uint8
    ys, = (image.min((1, 2)) < value).nonzero()
    xs, = (image.min(0).min(1) < value).nonzero()
    if len(xs) == 0 or len(ys) == 0:
        return image
    return image[ys.min():ys.max() + 1, xs.min():xs.max() + 1]