code: def __init__(self, num_classes, ignore_index=255):
      self.num_classes = num_classes
      self.ignore_index = ignore_index
      self._N = num_classes + 1  # Store ignore label in the last class
  
      self.conf_matrix = np.zeros((self._N, self._N), dtype=np.int64)
  
file_path: PaddleSeg/contrib/PanopticSeg/paddlepanseg/utils/evaluation/sem_seg_evaluator.py
imports: import numpy
  from paddlepanseg.cvlibs import build_info_dict
  from .evaluator import Evaluator
label_desc: Use image node_id 1 to create a new SemSegEvaluator object from inherited base classes: Evaluator with example: obj = SemSegEvaluator(num_classes, ignore_index)