make_hero.py

import skimage
import requests
import urllib.request
import io
from PIL import Image, ImageChops
import numpy as np


def make_hero(url):
    f = urllib.request.urlopen(url)
    f = io.BytesIO(f.read())

    img = Image.open(f).crop((0, 0, 720, 184)).resize((1800, 460)).convert("RGBA")
    mask = np.zeros(img.size, dtype="uint8")
    a = 600
    b = 1000
    mask[:a, :] = 255
    mask[a:b] = np.linspace(255, 0, b - a).reshape(-1, 1)

    mask = Image.fromarray(mask.T, mode="L")
    img.paste((0, 0, 0, 255), (0, 0), mask)
    return img