image_np_to_image_string.py

import base64
import cv2
from PIL import Image

cap = cv2.VideoCapture(0)
_, img = cap.read()
image_string = cv2.imencode(".png", img)[1].tostring()

output = io.BytesIO()
Image.fromarray(img).save(output, format='PNG')
buf = output.getvalue()
b64 = base64.b64encode(buf)

image_with_requests.py

import requests
from PIL import Image
from io import BytesIO
import numpy as np

res = requests.get(image_url)
image = Image.open(BytesIO(res.content))
image_array = np.array(image)