Convert Single mask image to polygon

[sctrueew]

Hi, Thanks for your work

How can I get polygon and points from an image? I use this but not working

Mask example:

import numpy as np
from imantics import Polygons, Mask
from PIL import Image
instance_path = r"test.png"
instance_image = Image.open(instance_path)
instance_array = np.array(instance_image)
polygons = Mask(instance_array).polygons()

print(polygons.points)
print(polygons.segmentation)