docstr: Normalize pixel values and pad to a square input.
docstr_tok: ["Normalize","pixel","values","and","pad","to","a","square","input","."]
code: def preprocess(self, x: torch.Tensor) -> torch.Tensor:
      """Normalize pixel values and pad to a square input."""
      # Normalize colors
      x = (x - self.pixel_mean) / self.pixel_std
  
      # Pad
      h, w = x.shape[-2:]
      padh = self.image_encoder.img_size - h
      padw = self.image_encoder.img_size - w
      x = F.pad(x, (0, padw, 0, padh))
      return x
  
file_path: segment-anything/segment_anything/modeling/sam.py
imports: import torch
  from torch import nn
  from torch.nn import functional
  from typing import Any, Dict, List, Tuple
  from .image_encoder import ImageEncoderViT
  from .mask_decoder import MaskDecoder
  from .prompt_encoder import PromptEncoder
label_desc: Use image node_id 5 for calling the Sam obj's underlying member method code with example usage: obj.preprocess(x) and returns: x