def export_2d_annotation(root_path, info_path, version, mono3d=False):
    """Export 2d annotation from the info file and raw data.

    Args:
        root_path (str): Root path of the raw data.
        info_path (str): Path of the info file.
        version (str): Dataset version.
        mono3d (bool): Whether to export mono3d annotation. Default: False.
    """
    # get bbox annotations for camera
    camera_types = [
        'CAM_FRONT',
        'CAM_FRONT_RIGHT',
        'CAM_FRONT_LEFT',
        'CAM_BACK',
        'CAM_BACK_LEFT',
        'CAM_BACK_RIGHT',
    ]
    nusc_infos = mmcv.load(info_path)['infos']
    nusc = NuScenes(version=version, dataroot=root_path, verbose=True)
    # info_2d_list = []
    cat2Ids = [
        dict(id=nus_categories.index(cat_name), name=cat_name)
        for cat_name in nus_categories
    ]
    coco_ann_id = 0
    coco_2d_dict = dict(annotations=[], images=[], categories=cat2Ids)
    for info in mmcv.track_iter_progress(nusc_infos):
        for cam in camera_types:
            cam_info = info['cams'][cam]
            coco_infos = get_2d_boxes(
                nusc,
                cam_info['sample_data_token'],
                visibilities=['', '1', '2', '3', '4'],
                mono3d=mono3d)
            (height, width, _) = mmcv.imread(cam_info['data_path']).shape
            coco_2d_dict['images'].append(
                dict(
                    file_name=cam_info['data_path'].split('data/nuscenes/')
                    [-1],
                    id=cam_info['sample_data_token'],
                    token=info['token'],
                    cam2ego_rotation=cam_info['sensor2ego_rotation'],
                    cam2ego_translation=cam_info['sensor2ego_translation'],
                    ego2global_rotation=info['ego2global_rotation'],
                    ego2global_translation=info['ego2global_translation'],
                    cam_intrinsic=cam_info['cam_intrinsic'],
                    width=width,
                    height=height))
            for coco_info in coco_infos:
                if coco_info is None:
                    continue
                # add an empty key for coco format
                coco_info['segmentation'] = []
                coco_info['id'] = coco_ann_id
                coco_2d_dict['annotations'].append(coco_info)
                coco_ann_id += 1
    if mono3d:
        json_prefix = f'{info_path[:-4]}_mono3d'
    else:
        json_prefix = f'{info_path[:-4]}'
    mmcv.dump(coco_2d_dict, f'{json_prefix}.coco.json')
Export 2d annotation from the info file and raw data.

    Args:
        root_path (str): Root path of the raw data.
        info_path (str): Path of the info file.
        version (str): Dataset version.
        mono3d (bool): Whether to export mono3d annotation. Default: False.
    
tools/data_converter/vad_nuscenes_converter.py