The Bungie Clan Banner images are generated from multiple images. The real way to get these images can be found here https://github.com/xlxCLUxlx/Destiny2API/wiki/Building-Your-Clan-Banner:--How-To
You can also use Selenium, an HTML parser, and a base64 decoder to "cheat" at getting the clan banner images from Bungie.net. You need Selenium because the images are generated via Javascript so a simple curl/wget won't find them. Here is a quick and dirty Python3.6 script to show the idea.
#!/usr/bin/env python
"""
Get clan banner image from bungie.net
Download Chrome driver from
https://chromedriver.storage.googleapis.com/2.33/chromedriver_linux64.zip
and unzip into working directory
"""
import base64
from bs4 import BeautifulSoup
from selenium import webdriver
from selenium.webdriver.chrome.options import Options
def main():
"""
Use Selenium and BeautifulSoup for fun and profit
"""
options = Options()
options.add_argument('--headless')
options.add_argument('start-maximized')
driver = webdriver.Chrome(executable_path='./chromedriver', chrome_options=options)
driver.implicitly_wait(10)
driver.get('https://www.bungie.net/en/ClanV2?groupId=2080464')
html = driver.execute_script('return document.body.innerHTML')
driver.close()
soup = BeautifulSoup(html, 'html.parser')
bdiv = soup.find('div', {'id': 'ClanBanner'})
img = bdiv['style']
img = img.replace('background-image: url("data:image/png;base64,', '')
img = img.replace('");', '')
with open('clanbanner.png', 'wb') as outfile:
outfile.write(base64.urlsafe_b64decode(img))
if __name__ == '__main__':
main()