code: def strip_mask(mask):
      row = mask[0, 0, :]
      col = mask[0, :, 0]
      im_h = len(col) - np.count_nonzero(col == -1)
      im_w = len(row) - np.count_nonzero(row == -1)
      return mask[:, :im_h, :im_w]
  
file_path: PaddleDetection/ppdet/metrics/json_results.py
imports: import six
  import numpy
label_desc: Use image node_id 3 for calling a global function with example usage: strip_mask(mask) and returns: mask