Transforming coordinates to pixels.

    Arguments:
        y : np array
            vector in which (y[0], y[1]) and (y[2], y[3]) are the
            the corners of a bounding box.
        x : image
            an image
    Returns:
        Y : image
            of shape x.shape

def coords2px(y, x):
    """ Transforming coordinates to pixels.

    Arguments:
        y : np array
            vector in which (y[0], y[1]) and (y[2], y[3]) are the
            the corners of a bounding box.
        x : image
            an image
    Returns:
        Y : image
            of shape x.shape
    """
    rows = np.rint([y[0], y[0], y[2], y[2]]).astype(int)
    cols = np.rint([y[1], y[3], y[1], y[3]]).astype(int)
    r,c,*_ = x.shape
    Y = np.zeros((r, c))
    Y[rows, cols] = 1
    return Y