original_docstring: 
      Create semantic segmentation annotations from panoptic segmentation
      annotations, to be used by PanopticFPN.
  
      It maps all thing categories to class 0, and maps all unlabeled pixels to class 255.
      It maps all stuff categories to contiguous ids starting from 1.
  
      Args:
          panoptic_json (str): path to the panoptic json file, in COCO's format.
          panoptic_root (str): a directory with panoptic annotation files, in COCO's format.
          sem_seg_root (str): a directory to output semantic annotation files
          categories (list[dict]): category metadata. Each dict needs to have:
              "id": corresponds to the "category_id" in the json annotations
              "isthing": 0 or 1
      
docstring: Create semantic segmentation annotations from panoptic segmentation
  annotations, to be used by PanopticFPN.
  
  It maps all thing categories to class 0, and maps all unlabeled pixels to class 255.
  It maps all stuff categories to contiguous ids starting from 1.
docstring_tokens: Create semantic segmentation annotations from panoptic segmentation annotations to be used by PanopticFPN . It maps all thing categories to class 0 and maps all unlabeled pixels to class 255 . It maps all stuff categories to contiguous ids starting from 1 .
code: def separate_coco_semantic_from_panoptic(panoptic_json, panoptic_root, sem_seg_root, categories):
      """
      Create semantic segmentation annotations from panoptic segmentation
      annotations, to be used by PanopticFPN.
  
      It maps all thing categories to class 0, and maps all unlabeled pixels to class 255.
      It maps all stuff categories to contiguous ids starting from 1.
  
      Args:
          panoptic_json (str): path to the panoptic json file, in COCO's format.
          panoptic_root (str): a directory with panoptic annotation files, in COCO's format.
          sem_seg_root (str): a directory to output semantic annotation files
          categories (list[dict]): category metadata. Each dict needs to have:
              "id": corresponds to the "category_id" in the json annotations
              "isthing": 0 or 1
      """
      os.makedirs(sem_seg_root, exist_ok=True)
  
      stuff_ids = [k["id"] for k in categories if k["isthing"] == 0]
      thing_ids = [k["id"] for k in categories if k["isthing"] == 1]
      id_map = {}  # map from category id to id in the output semantic annotation
      assert len(stuff_ids) <= 254
      for i, stuff_id in enumerate(stuff_ids):
          id_map[stuff_id] = i + 1
      for thing_id in thing_ids:
          id_map[thing_id] = 0
      id_map[0] = 255
  
      with open(panoptic_json) as f:
          obj = json.load(f)
  
      pool = mp.Pool(processes=max(mp.cpu_count() // 2, 4))
  
      def iter_annotations():
          for anno in obj["annotations"]:
              file_name = anno["file_name"]
              segments = anno["segments_info"]
              input = os.path.join(panoptic_root, file_name)
              output = os.path.join(sem_seg_root, file_name)
              yield input, output, segments
  
      print("Start writing to {} ...".format(sem_seg_root))
      start = time.time()
      pool.starmap(
          functools.partial(_process_panoptic_to_semantic, id_map=id_map),
          iter_annotations(),
          chunksize=100,
      )
      print("Finished. time: {:.2f}s".format(time.time() - start))
code_tokens: def separate_coco_semantic_from_panoptic ( panoptic_json , panoptic_root , sem_seg_root , categories ) : os . makedirs ( sem_seg_root , exist_ok = True ) stuff_ids = [ k [ "id" ] for k in categories if k [ "isthing" ] == 0 ] thing_ids = [ k [ "id" ] for k in categories if k [ "isthing" ] == 1 ] id_map = { } assert len ( stuff_ids ) <= 254 for i , stuff_id in enumerate ( stuff_ids ) : id_map [ stuff_id ] = i + 1 for thing_id in thing_ids : id_map [ thing_id ] = 0 id_map [ 0 ] = 255 with open ( panoptic_json ) as f : obj = json . load ( f ) pool = mp . Pool ( processes = max ( mp . cpu_count ( ) // 2 , 4 ) ) def iter_annotations ( ) : for anno in obj [ "annotations" ] : file_name = anno [ "file_name" ] segments = anno [ "segments_info" ] input = os . path . join ( panoptic_root , file_name ) output = os . path . join ( sem_seg_root , file_name ) yield input , output , segments print ( "Start writing to {} ..." . format ( sem_seg_root ) ) start = time . time ( ) pool . starmap ( functools . partial ( _process_panoptic_to_semantic , id_map = id_map ) , iter_annotations ( ) , chunksize = 100 , ) print ( "Finished. time: {:.2f}s" . format ( time . time ( ) - start ) )
short_docstring: Create semantic segmentation annotations from panoptic segmentation
  annotations, to be used by PanopticFPN.
short_docstring_tokens: Create semantic segmentation annotations from panoptic segmentation annotations to be used by PanopticFPN .
comment: """
      Create semantic segmentation annotations from panoptic segmentation
      annotations, to be used by PanopticFPN.
  
      It maps all thing categories to class 0, and maps all unlabeled pixels to class 255.
      It maps all stuff categories to contiguous ids starting from 1.
  
      Args:
          panoptic_json (str): path to the panoptic json file, in COCO's format.
          panoptic_root (str): a directory with panoptic annotation files, in COCO's format.
          sem_seg_root (str): a directory to output semantic annotation files
          categories (list[dict]): category metadata. Each dict needs to have:
              "id": corresponds to the "category_id" in the json annotations
              "isthing": 0 or 1
      """$SEP$# map from category id to id in the output semantic annotation