def _get_imu2cam_transform(self, image_file):
"""Gets the transformation between IMU an camera from an image file"""
parent_folder = self._get_parent_folder(image_file)
if image_file in self.imu2velo_calib_cache:
return self.imu2velo_calib_cache[image_file]
cam2cam = read_calib_file(os.path.join(parent_folder, CALIB_FILE['cam2cam']))
imu2velo = read_calib_file(os.path.join(parent_folder, CALIB_FILE['imu2velo']))
velo2cam = read_calib_file(os.path.join(parent_folder, CALIB_FILE['velo2cam']))
velo2cam_mat = transform_from_rot_trans(velo2cam['R'], velo2cam['T'])
imu2velo_mat = transform_from_rot_trans(imu2velo['R'], imu2velo['T'])
cam_2rect_mat = transform_from_rot_trans(cam2cam['R_rect_00'], np.zeros(3))
imu2cam = cam_2rect_mat @ velo2cam_mat @ imu2velo_mat
self.imu2velo_calib_cache[image_file] = imu2cam
return imu2cam
def _read_raw_calib_file(folder):
"""Read raw calibration files from folder."""
return read_calib_file(os.path.join(folder, CALIB_FILE['cam2cam']))