class_docstr: Crop the given image at the center
docstr: Args:
      img (numpy.ndarray): Images to be cropped.
  Returns:
      numpy.ndarray: Cropped image.
docstr_tok: ["Args",":","img","(","numpy.ndarray",")",":","Images","to","be","cropped",".","Returns",":","numpy.ndarray",":","Cropped","image","."]
code: def __call__(self, frames):
      """
      Args:
          img (numpy.ndarray): Images to be cropped.
      Returns:
          numpy.ndarray: Cropped image.
      """
      t, h, w = frames.shape
      th, tw = self.size
      delta_w = int(round((w - tw)) / 2.0)
      delta_h = int(round((h - th)) / 2.0)
      frames = frames[:, delta_h : delta_h + th, delta_w : delta_w + tw]
      return frames
  
imports: import random
  import cv2
  import numpy
  import torch
  from scipy import signal
label_desc: Use image node_id 2 for calling the CenterCrop obj's underlying member method code with example usage: obj.__call__(frames) and returns: frames