def _load_imgs(file_paths, slice_, color, resize):
    """Internally used to load images"""

    # Try to import imread and imresize from PIL. We do this here to prevent
    # the whole sklearn.datasets module from depending on PIL.
    try:
        try:
            from scipy.misc import imread
        except ImportError:
            from scipy.misc.pilutil import imread
        from scipy.misc import imresize
    except ImportError:
        raise ImportError("The Python Imaging Library (PIL)"
                          " is required to load data from jpeg files")

    # compute the portion of the images to load to respect the slice_ parameter
    # given by the caller
    default_slice = (slice(0, 250), slice(0, 250))
    if slice_ is None:
        slice_ = default_slice
    else:
        slice_ = tuple(s or ds for s, ds in zip(slice_, default_slice))

    h_slice, w_slice = slice_
    h = (h_slice.start - h_slice.stop) // (h_slice.step or 1)
    w = (w_slice.stop - w_slice.start) // (w_slice.step or 1)

    if resize is not None:
        resize = float(resize)
        h = int(resize * h)
        w = int(resize * w)

    # allocate some contiguous memory to host the decoded image slices
    n_faces = len(file_paths)
    if not color:
        faces = np.zeros((n_faces, h, w), dtype=np.float32)
    else:
        faces = np.zeros((n_faces, h, w, 3), dtype=np.float32)

    # iterate over the collected file path to load the jpeg files as numpy
    # arrays
    for i, file_path in enumerate(file_paths):
        if i % 1000 == 0:
            logger.info("Loading face #%05d / %05d", i + 1, n_faces)

        # Checks if jpeg reading worked. Refer to issue #3594 for more
        # details.
        img = imread(file_path)
        if img.ndim is 0:
            raise RuntimeError("Failed to read the image file %s, "
                               "Please make sure that libjpeg is installed"
                               % file_path)

        face = np.asarray(img[slice_], dtype=np.float32)
        face /= 255.0  # scale uint8 coded colors to the [0.0, 1.0] floats
        if resize is not None:
            face = imresize(face, resize)
        if not color:
            # average the color channels to compute a gray levels
            # representation
            face = face.mean(axis=2)

        faces[i, ...] = face

    return faces


#
# Task #1:  Face Identification on picture with names
#
dataset/ETHPy150Open scikit-learn/scikit-learn/sklearn/datasets/lfw.py/_load_imgs/swapped operands of `-`