docstr: interpolation data buffer to make the signal become more periodic (advoid spectral leakage)
code: def interpolation(self, data_buffer, times):
      """
      interpolation data buffer to make the signal become more periodic (advoid spectral leakage)
      """
      L = len(data_buffer)
  
      even_times = np.linspace(times[0], times[-1], L)
  
      interp = np.interp(even_times, times, data_buffer)
      interpolated_data = np.hamming(L) * interp
      return interpolated_data
  
file_path: heart-rate-measurement-camera/signal_processing.py
imports: import cv2
  import numpy
  import time
  from scipy import signal
label_desc: Use image node_id 5 for calling the Signal_processing obj's underlying member method code with example usage: obj.interpolation(data_buffer, times) and returns: interpolated_data