def xyxy_to_xywh(xyxy):
    """" Calculates the relative bounding box from absolute pixel values. """
    bbox_left = min([xyxy[0], xyxy[2]])
    bbox_top = min([xyxy[1], xyxy[3]])
    bbox_w = abs(xyxy[0] - xyxy[2])
    bbox_h = abs(xyxy[1] - xyxy[3])
    x_c = (bbox_left + bbox_w / 2)
    y_c = (bbox_top + bbox_h / 2)
    w = bbox_w
    h = bbox_h
    return [x_c, y_c, w, h]


def tlwh_to_xyxy(tlwh):
    """" Convert tlwh to xyxy """
    x1 = tlwh[0]
    y1 = tlwh[1]
    x2 = tlwh[2] + x1
    y2 = tlwh[3] + y1
    return [x1, y1, x2, y2]


def xyxy_to_tlwh(bbox_xyxy):
    tlwh_bboxs = []
    for i, box in enumerate(bbox_xyxy):
        x1, y1, x2, y2 = [int(i) for i in box]
        top = x1
        left = y1
        w = int(x2 - x1)
        h = int(y2 - y1)
        tlwh_obj = [top, left, w, h]
        tlwh_bboxs.append(tlwh_obj)
    return tlwh_bboxs