Method get_iphone_extrinsics

detrsmpl/data/data_structures/smc_reader.py:253–305

Get extrinsics(cam2world) of an iPhone RGB camera by iPhone id. Args: iphone_id (int, optional): ID of an iPhone, starts from 0. Defaults to 0. homogeneous (bool, optional): If true, returns rotation and translation in

(self,
                              iphone_id=0,
                              homogeneous=True,
                              vertical=True)

        return intrinsics

    def get_iphone_extrinsics(self,
                              iphone_id=0,
                              homogeneous=True,
                              vertical=True):
        """Get extrinsics(cam2world) of an iPhone RGB camera by iPhone id.

        Args:
            iphone_id (int, optional):
                ID of an iPhone, starts from 0.
                Defaults to 0.
            homogeneous (bool, optional):
                If true, returns rotation and translation in
                one 4x4 matrix. Defaults to True.
            vertical (bool, optional):
                iPhone assumes landscape orientation
                if True, convert data to vertical orientation
                Defaults to True.

        Returns:
            homogeneous is True
                ndarray: A 4x4 transformation matrix(cam2world).
            homogeneous is False
                dict: A dict of rotation and translation,
                    keys are R and T,
                    each value is an ndarray.
        """
        if iphone_id != 0:
            raise KeyError('Currently only one iPhone.')
        R = np.asarray(self.calibration_dict['iPhone']['R']).reshape(3, 3)
        T = np.asarray(self.calibration_dict['iPhone']['T']).reshape(3)

        # cam2world
        extrinsics = np.identity(4, dtype=float)
        extrinsics[:3, :3] = R
        extrinsics[:3, 3] = T

        # Extrinsics have to be adjusted to achieve rotation
        # A rotation matrix is applied on the extrinsics
        if vertical:
            # 90-degree clockwise rotation around z-axis
            R = np.eye(4)
            R[:2, :2] = np.array([[0, -1], [1, 0]])
            # Note the extrinsics is cam2world
            # world2cam_adjusted = R @ world2cam
            # => cam2world_adjusted = cam2world @ inv(R)
            extrinsics = extrinsics @ np.linalg.inv(R)
            R = extrinsics[:3, :3]
            T = extrinsics[:3, 3]

        if homogeneous:
            return extrinsics
        else:
            return {'R': R, 'T': T}

    def get_iphone_color_resolution(self, iphone_id=0, vertical=True):
        """Get color image resolution of an iPhone RGB camera by iPhone id.