docstr: normalize the input data buffer
code: def normalization(self, data_buffer):
      """
      normalize the input data buffer
      """
  
      # normalized_data = (data_buffer - np.mean(data_buffer))/np.std(data_buffer)
      normalized_data = data_buffer / np.linalg.norm(data_buffer)
  
      return normalized_data
  
file_path: heart-rate-measurement-camera/new_update/signal_processing.py
imports: import cv2
  import numpy
  import time
  from scipy import signal
label_desc: Use image node_id 3 for calling the Signal_processing obj's underlying member method code with example usage: obj.normalization(data_buffer) and returns: normalized_data