docstr: Args:
      max_val: maximum value of the input tensor. This refers to the maximum domain value of the input tensor.
code: def __init__(self, max_val: float = 256) -> None:
      """
      Args:
          max_val: maximum value of the input tensor. This refers to the maximum domain value of the input tensor.
  
      """
      super().__init__()
      self.max_val = max_val
  
imports: from typing import List, Optional
  import torch
  from torch import nn, Tensor
  from torch.nn import functional
  from torchvision.prototype.models.depth.stereo.raft_stereo import grid_sample, make_coords_grid
label_desc: Use image node_id 1 to create a new PSNRLoss object from inherited base classes: nn with example: obj = PSNRLoss(max_val)