code: def __init__(self, method="sparseOptFlow", downscale=2, verbose=None):
      super(GMC, self).__init__()
  
      self.method = method
      self.downscale = max(1, int(downscale))
  
      if self.method == "orb":
          self.detector = cv2.FastFeatureDetector_create(20)
          self.extractor = cv2.ORB_create()
          self.matcher = cv2.BFMatcher(cv2.NORM_HAMMING)
  
      elif self.method == "sift":
          self.detector = cv2.SIFT_create(
              nOctaveLayers=3, contrastThreshold=0.02, edgeThreshold=20
          )
          self.extractor = cv2.SIFT_create(
              nOctaveLayers=3, contrastThreshold=0.02, edgeThreshold=20
          )
          self.matcher = cv2.BFMatcher(cv2.NORM_L2)
  
      elif self.method == "ecc":
          number_of_iterations = 5000
          termination_eps = 1e-6
          self.warp_mode = cv2.MOTION_EUCLIDEAN
          self.criteria = (
              cv2.TERM_CRITERIA_EPS | cv2.TERM_CRITERIA_COUNT,
              number_of_iterations,
              termination_eps,
          )
  
      elif self.method == "sparseOptFlow":
          self.feature_params = dict(
              maxCorners=1000,
              qualityLevel=0.01,
              minDistance=1,
              blockSize=3,
              useHarrisDetector=False,
              k=0.04,
          )
          # self.gmc_file = open('GMC_results.txt', 'w')
  
      elif self.method == "file" or self.method == "files":
          seqName = verbose[0]
          ablation = verbose[1]
          if ablation:
              filePath = r"tracker/GMC_files/MOT17_ablation"
          else:
              filePath = r"tracker/GMC_files/MOTChallenge"
  
          if "-FRCNN" in seqName:
              seqName = seqName[:-6]
          elif "-DPM" in seqName:
              seqName = seqName[:-4]
          elif "-SDP" in seqName:
              seqName = seqName[:-4]
  
          self.gmcFile = open(
              filePath + "/GMC-" + seqName + ".txt", "r"
          )
  
          if self.gmcFile is None:
              raise ValueError(
                  "Error: Unable to open GMC file in directory:"
                  + filePath
              )
      elif self.method == "none" or self.method == "None":
          self.method = "none"
      else:
          raise ValueError("Error: Unknown CMC method:" + method)
  
      self.prevFrame = None
      self.prevKeyPoints = None
      self.prevDescriptors = None
  
      self.initializedFirstFrame = False
  
file_path: PaddleDetection/deploy/pptracking/python/mot/motion/gmc.py
imports: import cv2
  import matplotlib.pyplot
  import numpy
  import copy
  import time
label_desc: Use image node_id 1 to create a new GMC object  with example: obj = GMC(method, downscale, verbose)