new_contents: import numpy
  from PIL import Image, ImageDraw
  import cv2
  
  polygon = [(1,1),(100,20),(120, 130), (12, 120)]
  width = 299
  height = 299
  
  img = Image.new('L', (width, height), 0)
  ImageDraw.Draw(img).polygon(polygon, outline=1, fill=1)
  mask = numpy.array(img)
  print(mask)
  cv2.imshow("mask", mask * 255)
  cv2.waitKey(0)
  
  
subject: add draw mask