def convert_point()

in easycv/core/bbox/structures/coord_3d_mode.py [0:0]


    def convert_point(point, src, dst, rt_mat=None):
        """Convert points from `src` mode to `dst` mode.

        Args:
            point (tuple | list | np.ndarray |
                torch.Tensor | :obj:`BasePoints`):
                Can be a k-tuple, k-list or an Nxk array/tensor.
            src (:obj:`CoordMode`): The src Point mode.
            dst (:obj:`CoordMode`): The target Point mode.
            rt_mat (np.ndarray | torch.Tensor, optional): The rotation and
                translation matrix between different coordinates.
                Defaults to None.
                The conversion from `src` coordinates to `dst` coordinates
                usually comes along the change of sensors, e.g., from camera
                to LiDAR. This requires a transformation matrix.

        Returns:
            (tuple | list | np.ndarray | torch.Tensor | :obj:`BasePoints`):
                The converted point of the same type.
        """
        if src == dst:
            return point

        is_numpy = isinstance(point, np.ndarray)
        is_InstancePoints = isinstance(point, BasePoints)
        single_point = isinstance(point, (list, tuple))
        if single_point:
            assert len(point) >= 3, (
                'CoordMode.convert takes either a k-tuple/list or '
                'an Nxk array/tensor, where k >= 3')
            arr = torch.tensor(point)[None, :]
        else:
            # avoid modifying the input point
            if is_numpy:
                arr = torch.from_numpy(np.asarray(point)).clone()
            elif is_InstancePoints:
                arr = point.tensor.clone()
            else:
                arr = point.clone()

        # convert point from `src` mode to `dst` mode.
        if src == Coord3DMode.LIDAR and dst == Coord3DMode.CAM:
            if rt_mat is None:
                rt_mat = arr.new_tensor([[0, -1, 0], [0, 0, -1], [1, 0, 0]])
        elif src == Coord3DMode.CAM and dst == Coord3DMode.LIDAR:
            if rt_mat is None:
                rt_mat = arr.new_tensor([[0, 0, 1], [-1, 0, 0], [0, -1, 0]])
        elif src == Coord3DMode.DEPTH and dst == Coord3DMode.CAM:
            if rt_mat is None:
                rt_mat = arr.new_tensor([[1, 0, 0], [0, 0, -1], [0, 1, 0]])
        elif src == Coord3DMode.CAM and dst == Coord3DMode.DEPTH:
            if rt_mat is None:
                rt_mat = arr.new_tensor([[1, 0, 0], [0, 0, 1], [0, -1, 0]])
        elif src == Coord3DMode.LIDAR and dst == Coord3DMode.DEPTH:
            if rt_mat is None:
                rt_mat = arr.new_tensor([[0, -1, 0], [1, 0, 0], [0, 0, 1]])
        elif src == Coord3DMode.DEPTH and dst == Coord3DMode.LIDAR:
            if rt_mat is None:
                rt_mat = arr.new_tensor([[0, 1, 0], [-1, 0, 0], [0, 0, 1]])
        else:
            raise NotImplementedError(
                f'Conversion from Coord3DMode {src} to {dst} '
                'is not supported yet')

        if not isinstance(rt_mat, torch.Tensor):
            rt_mat = arr.new_tensor(rt_mat)
        if rt_mat.size(1) == 4:
            extended_xyz = torch.cat(
                [arr[..., :3], arr.new_ones(arr.size(0), 1)], dim=-1)
            xyz = extended_xyz @ rt_mat.t()
        else:
            xyz = arr[..., :3] @ rt_mat.t()

        remains = arr[..., 3:]
        arr = torch.cat([xyz[..., :3], remains], dim=-1)

        # convert arr to the original type
        original_type = type(point)
        if single_point:
            return original_type(arr.flatten().tolist())
        if is_numpy:
            return arr.numpy()
        elif is_InstancePoints:
            if dst == Coord3DMode.CAM:
                target_type = CameraPoints
            elif dst == Coord3DMode.LIDAR:
                target_type = LiDARPoints
            elif dst == Coord3DMode.DEPTH:
                target_type = DepthPoints
            else:
                raise NotImplementedError(
                    f'Conversion to {dst} through {original_type}'
                    ' is not supported yet')
            return target_type(
                arr,
                points_dim=arr.size(-1),
                attribute_dims=point.attribute_dims)
        else:
            return arr