def boxes_xyxy_rel_to_abs(bboxes, img_shape):
    """ Converts boxes from relative to absolute coordinates 

    bboxes: array of boxes in XYXY relative coordinates
    img_shape: tuple (height, width)
    """

    h, w = img_shape
    bboxes[:, ::2] = bboxes[:, ::2] * w
    bboxes[:, 1::2] = bboxes[:, 1::2] * h

    return bboxes