code: def __init__(self, main_indicator="all", **kwargs):
      self.main_indicator = main_indicator
      self.eps = 1e-5
      self.psnr_result = []
      self.ssim_result = []
      self.calculate_ssim = SSIM()
      self.reset()
  
imports: from math import exp
  import paddle
  import paddle.nn.functional
  import paddle.nn
  import string
label_desc: Use image node_id 1 to create a new SRMetric object from inherited base classes: object with example: obj = SRMetric(main_indicator)